Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Fixing usage of clustered datastore name to be absolute datastore name

**What this PR does / why we need it**:
This PR adds the step to convert the datastore name in form of a folder/cluster to absolute datastore name.

**Which issue this PR fixes**: fixes vmware#312 

**Special notes for your reviewer**:
Testing. All the clustered datastore tests pass now
```
root@k8s-dev-vm-01:~/shahzeb/k8s/kubernetes# export CLUSTER_DATASTORE=dscl1/sharedVmfs-0
root@k8s-dev-vm-01:~/shahzeb/k8s/kubernetes# export VSPHERE_SPBM_POLICY_DS_CLUSTER=gold_cluster
root@k8s-dev-vm-01:~/shahzeb/k8s/kubernetes# go run hack/e2e.go --check-version-skew=false --v --test  --test_args='--ginkgo.focus=Volume\sProvisioning\sOn\sClustered\sDatastore'
flag provided but not defined: -check-version-skew
Usage of /tmp/go-build641208048/command-line-arguments/_obj/exe/e2e:
  -get
    	go get -u kubetest if old or not installed (default true)
  -old duration
    	Consider kubetest old if it exceeds this (default 24h0m0s)
2017/10/18 17:29:39 e2e.go:55: NOTICE: go run hack/e2e.go is now a shim for test-infra/kubetest
2017/10/18 17:29:39 e2e.go:56:   Usage: go run hack/e2e.go [--get=true] [--old=24h0m0s] -- [KUBETEST_ARGS]
2017/10/18 17:29:39 e2e.go:57:   The separator is required to use --get or --old flags
2017/10/18 17:29:39 e2e.go:58:   The -- flag separator also suppresses this message
2017/10/18 17:29:39 e2e.go:77: Calling kubetest --check-version-skew=false --v --test --test_args=--ginkgo.focus=Volume\sProvisioning\sOn\sClustered\sDatastore...
2017/10/18 17:29:39 util.go:154: Running: ./cluster/kubectl.sh --match-server-version=false version
2017/10/18 17:29:39 util.go:156: Step './cluster/kubectl.sh --match-server-version=false version' finished in 286.302987ms
2017/10/18 17:29:39 util.go:154: Running: ./hack/e2e-internal/e2e-status.sh
Skeleton Provider: prepare-e2e not implemented
Client Version: version.Info{Major:"1", Minor:"6+", GitVersion:"v1.6.0-alpha.0.17675+2bfcf4a7d1d6d4-dirty", GitCommit:"2bfcf4a7d1d6d4f257fe7ee96dcb47484b8e3a5f", GitTreeState:"dirty", BuildDate:"2017-10-18T23:37:58Z", GoVersion:"go1.9.1", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"6+", GitVersion:"v1.6.0-alpha.0.17663+ba93892625a3e8", GitCommit:"ba93892625a3e8a246f3bc660d56a2635e7e7f9f", GitTreeState:"clean", BuildDate:"2017-10-18T20:57:49Z", GoVersion:"go1.9.1", Compiler:"gc", Platform:"linux/amd64"}
2017/10/18 17:29:40 util.go:156: Step './hack/e2e-internal/e2e-status.sh' finished in 296.318449ms
2017/10/18 17:29:40 util.go:154: Running: ./hack/ginkgo-e2e.sh --ginkgo.focus=Volume\sProvisioning\sOn\sClustered\sDatastore
Conformance test: not doing test setup.
Oct 18 17:29:41.634: INFO: Overriding default scale value of zero to 1
Oct 18 17:29:41.634: INFO: Overriding default milliseconds value of zero to 5000
I1018 17:29:41.829967   32645 e2e.go:383] Starting e2e run "98fbc41f-b464-11e7-8e40-0050569c27f6" on Ginkgo node 1
Running Suite: Kubernetes e2e suite
===================================
Random Seed: 1508372981 - Will randomize all specs
Will run 3 of 714 specs

Oct 18 17:29:41.889: INFO: >>> kubeConfig: /tmp/kube171.json
Oct 18 17:29:41.894: INFO: Waiting up to 4h0m0s for all (but 0) nodes to be schedulable
Oct 18 17:29:41.928: INFO: Waiting up to 10m0s for all pods (need at least 0) in namespace 'kube-system' to be running and ready
Oct 18 17:29:42.057: INFO: 13 / 13 pods in namespace 'kube-system' are running and ready (0 seconds elapsed)
Oct 18 17:29:42.057: INFO: expected 4 pod replicas in namespace 'kube-system', 4 are Running and Ready.
Oct 18 17:29:42.063: INFO: Waiting for pods to enter Success, but no pods in "kube-system" match label map[name:e2e-image-puller]
Oct 18 17:29:42.063: INFO: Dumping network health container logs from all nodes...
Oct 18 17:29:42.076: INFO: Client version: v1.6.0-alpha.0.17675+2bfcf4a7d1d6d4-dirty
Oct 18 17:29:42.079: INFO: Server version: v1.6.0-alpha.0.17663+ba93892625a3e8
SSSS
------------------------------
[sig-storage] Volume Provisioning On Clustered Datastore [Feature:vsphere]
  verify static provisioning on clustered datastore
  /go/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/test/e2e/storage/vsphere_volume_cluster_ds.go:70
[BeforeEach] [sig-storage] Volume Provisioning On Clustered Datastore [Feature:vsphere]
  /go/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/test/e2e/framework/framework.go:133
STEP: Creating a kubernetes client
Oct 18 17:29:42.079: INFO: >>> kubeConfig: /tmp/kube171.json
STEP: Building a namespace api object
STEP: Waiting for a default service account to be provisioned in namespace
[BeforeEach] [sig-storage] Volume Provisioning On Clustered Datastore [Feature:vsphere]
  /go/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/test/e2e/storage/vsphere_volume_cluster_ds.go:50
[It] verify static provisioning on clustered datastore
  /go/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/test/e2e/storage/vsphere_volume_cluster_ds.go:70
STEP: creating a test vsphere volume
W1018 17:29:43.087373   32645 datacenter.go:156] QueryVirtualDiskUuid failed for diskPath: "[sharedVmfs-0] kubevols/kube-dummyDisk.vmdk". err: ServerFaultCode: File [sharedVmfs-0] kubevols/kube-dummyDisk.vmdk was not found
STEP: Creating pod
STEP: Waiting for pod to be ready
STEP: Verifying volume is attached
STEP: Deleting pod
Oct 18 17:30:07.268: INFO: Deleting pod "vsphere-e2e-vtzbg" in namespace "e2e-tests-volume-provision-bchh4"
Oct 18 17:30:07.301: INFO: Wait up to 5m0s for pod "vsphere-e2e-vtzbg" to be fully deleted
STEP: Waiting for volumes to be detached from the node
Oct 18 17:30:49.429: INFO: Volume "[dscl1/sharedVmfs-0] kubevols/e2e-vmdk-e2e-tests-volume-provision-bchh4.vmdk" appears to have successfully detached from "kubernetes-node4".
STEP: Deleting the vsphere volume
[AfterEach] [sig-storage] Volume Provisioning On Clustered Datastore [Feature:vsphere]
  /go/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/test/e2e/framework/framework.go:134
Oct 18 17:30:49.774: INFO: Waiting up to 3m0s for all (but 0) nodes to be ready
STEP: Destroying namespace "e2e-tests-volume-provision-bchh4" for this suite.
Oct 18 17:30:58.203: INFO: namespace: e2e-tests-volume-provision-bchh4, resource: bindings, ignored listing per whitelist
Oct 18 17:30:58.225: INFO: namespace e2e-tests-volume-provision-bchh4 deletion completed in 8.444766463s

• [SLOW TEST:76.146 seconds]
[sig-storage] Volume Provisioning On Clustered Datastore [Feature:vsphere]
/go/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/test/e2e/storage/framework.go:22
  verify static provisioning on clustered datastore
  /go/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/test/e2e/storage/vsphere_volume_cluster_ds.go:70
------------------------------
SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS
------------------------------
[sig-storage] Volume Provisioning On Clustered Datastore [Feature:vsphere]
  verify dynamic provision with spbm policy on clustered datastore
  /go/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/test/e2e/storage/vsphere_volume_cluster_ds.go:131
[BeforeEach] [sig-storage] Volume Provisioning On Clustered Datastore [Feature:vsphere]
  /go/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/test/e2e/framework/framework.go:133
STEP: Creating a kubernetes client
Oct 18 17:30:58.231: INFO: >>> kubeConfig: /tmp/kube171.json
STEP: Building a namespace api object
STEP: Waiting for a default service account to be provisioned in namespace
[BeforeEach] [sig-storage] Volume Provisioning On Clustered Datastore [Feature:vsphere]
  /go/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/test/e2e/storage/vsphere_volume_cluster_ds.go:50
[It] verify dynamic provision with spbm policy on clustered datastore
  /go/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/test/e2e/storage/vsphere_volume_cluster_ds.go:131
STEP: Creating Storage Class With storage policy params
STEP: Creating PVC using the Storage Class
STEP: Waiting for claim to be in bound phase
Oct 18 17:30:58.402: INFO: Waiting up to 5m0s for PersistentVolumeClaim pvc-6dwrm to have phase Bound
Oct 18 17:30:58.410: INFO: PersistentVolumeClaim pvc-6dwrm found but phase is Pending instead of Bound.
Oct 18 17:31:00.416: INFO: PersistentVolumeClaim pvc-6dwrm found but phase is Pending instead of Bound.
Oct 18 17:31:02.430: INFO: PersistentVolumeClaim pvc-6dwrm found and phase=Bound (4.027818895s)
STEP: Creating pod to attach PV to the node
STEP: Verify the volume is accessible and available in the pod
Oct 18 17:31:26.666: INFO: Running '/root/shahzeb/k8s/kubernetes/_output/dockerized/bin/linux/amd64/kubectl --server=https://10.160.141.5 --kubeconfig=/tmp/kube171.json exec pvc-tester-hgcj6 --namespace=e2e-tests-volume-provision-sfbcf -- /bin/touch /mnt/volume1/emptyFile.txt'
Oct 18 17:31:27.171: INFO: stderr: ""
Oct 18 17:31:27.171: INFO: stdout: ""
STEP: Deleting pod
Oct 18 17:31:27.171: INFO: Deleting pod "pvc-tester-hgcj6" in namespace "e2e-tests-volume-provision-sfbcf"
Oct 18 17:31:27.202: INFO: Wait up to 5m0s for pod "pvc-tester-hgcj6" to be fully deleted
STEP: Waiting for volumes to be detached from the node
Oct 18 17:32:11.324: INFO: Volume "[sharedVmfs-0] kubevols/kubernetes-dynamic-pvc-c6d8e174-b464-11e7-8b86-005056b7d4e9.vmdk" appears to have successfully detached from "kubernetes-node2".
Oct 18 17:32:11.324: INFO: Deleting PersistentVolumeClaim "pvc-6dwrm"
[AfterEach] [sig-storage] Volume Provisioning On Clustered Datastore [Feature:vsphere]
  /go/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/test/e2e/framework/framework.go:134
Oct 18 17:32:11.393: INFO: Waiting up to 3m0s for all (but 0) nodes to be ready
STEP: Destroying namespace "e2e-tests-volume-provision-sfbcf" for this suite.
Oct 18 17:32:19.867: INFO: namespace: e2e-tests-volume-provision-sfbcf, resource: bindings, ignored listing per whitelist
Oct 18 17:32:19.876: INFO: namespace e2e-tests-volume-provision-sfbcf deletion completed in 8.460287539s

• [SLOW TEST:81.645 seconds]
[sig-storage] Volume Provisioning On Clustered Datastore [Feature:vsphere]
/go/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/test/e2e/storage/framework.go:22
  verify dynamic provision with spbm policy on clustered datastore
  /go/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/test/e2e/storage/vsphere_volume_cluster_ds.go:131
------------------------------
SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS
------------------------------
[sig-storage] Volume Provisioning On Clustered Datastore [Feature:vsphere]
  verify dynamic provision with default parameter on clustered datastore
  /go/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/test/e2e/storage/vsphere_volume_cluster_ds.go:121
[BeforeEach] [sig-storage] Volume Provisioning On Clustered Datastore [Feature:vsphere]
  /go/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/test/e2e/framework/framework.go:133
STEP: Creating a kubernetes client
Oct 18 17:32:19.878: INFO: >>> kubeConfig: /tmp/kube171.json
STEP: Building a namespace api object
STEP: Waiting for a default service account to be provisioned in namespace
[BeforeEach] [sig-storage] Volume Provisioning On Clustered Datastore [Feature:vsphere]
  /go/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/test/e2e/storage/vsphere_volume_cluster_ds.go:50
[It] verify dynamic provision with default parameter on clustered datastore
  /go/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/test/e2e/storage/vsphere_volume_cluster_ds.go:121
STEP: Creating Storage Class With storage policy params
STEP: Creating PVC using the Storage Class
STEP: Waiting for claim to be in bound phase
Oct 18 17:32:20.024: INFO: Waiting up to 5m0s for PersistentVolumeClaim pvc-zrcmm to have phase Bound
Oct 18 17:32:20.034: INFO: PersistentVolumeClaim pvc-zrcmm found but phase is Pending instead of Bound.
Oct 18 17:32:22.040: INFO: PersistentVolumeClaim pvc-zrcmm found and phase=Bound (2.016093024s)
STEP: Creating pod to attach PV to the node
STEP: Verify the volume is accessible and available in the pod
Oct 18 17:32:30.266: INFO: Running '/root/shahzeb/k8s/kubernetes/_output/dockerized/bin/linux/amd64/kubectl --server=https://10.160.141.5 --kubeconfig=/tmp/kube171.json exec pvc-tester-2hns4 --namespace=e2e-tests-volume-provision-llvbq -- /bin/touch /mnt/volume1/emptyFile.txt'
Oct 18 17:32:30.774: INFO: stderr: ""
Oct 18 17:32:30.774: INFO: stdout: ""
STEP: Deleting pod
Oct 18 17:32:30.774: INFO: Deleting pod "pvc-tester-2hns4" in namespace "e2e-tests-volume-provision-llvbq"
Oct 18 17:32:30.806: INFO: Wait up to 5m0s for pod "pvc-tester-2hns4" to be fully deleted
STEP: Waiting for volumes to be detached from the node
Oct 18 17:33:20.972: INFO: Volume "[dscl1/sharedVmfs-0] kubevols/kubernetes-dynamic-pvc-f77fba36-b464-11e7-8b86-005056b7d4e9.vmdk" appears to have successfully detached from "kubernetes-node4".
Oct 18 17:33:20.972: INFO: Deleting PersistentVolumeClaim "pvc-zrcmm"
[AfterEach] [sig-storage] Volume Provisioning On Clustered Datastore [Feature:vsphere]
  /go/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/test/e2e/framework/framework.go:134
Oct 18 17:33:21.100: INFO: Waiting up to 3m0s for all (but 0) nodes to be ready
STEP: Destroying namespace "e2e-tests-volume-provision-llvbq" for this suite.
Oct 18 17:33:29.490: INFO: namespace: e2e-tests-volume-provision-llvbq, resource: bindings, ignored listing per whitelist
Oct 18 17:33:29.554: INFO: namespace e2e-tests-volume-provision-llvbq deletion completed in 8.444585266s

• [SLOW TEST:69.676 seconds]
[sig-storage] Volume Provisioning On Clustered Datastore [Feature:vsphere]
/go/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/test/e2e/storage/framework.go:22
  verify dynamic provision with default parameter on clustered datastore
  /go/src/k8s.io/kubernetes/_output/dockerized/go/src/k8s.io/kubernetes/test/e2e/storage/vsphere_volume_cluster_ds.go:121
------------------------------
SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSOct 18 17:33:29.559: INFO: Running AfterSuite actions on all node
Oct 18 17:33:29.559: INFO: Running AfterSuite actions on node 1

Ran 3 of 714 Specs in 227.670 seconds
SUCCESS! -- 3 Passed | 0 Failed | 0 Pending | 711 Skipped PASS

Ginkgo ran 1 suite in 3m48.395491704s
Test Suite Passed
```


**Release note**:

```release-note
```