Automatic merge from submit-queue (batch tested with PRs 55908, 55829, 55293, 55653, 55665). 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>.

[bug fix] TestCascadingDeletion during pull-kubernetes-unit-test flaky

**What this PR does / why we need it**:
fix pull-kubernetes-unit-test flaky.

```
go test -v k8s.io/kubernetes/test/integration/garbagecollector -run TestCascadingDeletion$
panic: close of closed channel
/go/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/vendor/k8s.io/apimachinery/pkg/util/runtime/runtime.go:58 +0x111
/usr/local/go/src/runtime/panic.go:491 +0x283
/go/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/pkg/controller/garbagecollector/graph_builder.go:259 +0xb80
/go/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/pkg/controller/garbagecollector/garbagecollector.go:123 +0x39
/go/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/pkg/controller/garbagecollector/garbagecollector.go:211 +0x20f
/go/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/vendor/k8s.io/apimachinery/pkg/util/wait/wait.go:133 +0x5e
/go/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/vendor/k8s.io/apimachinery/pkg/util/wait/wait.go:134 +0xbd
/go/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/vendor/k8s.io/apimachinery/pkg/util/wait/wait.go:88 +0x4d
/go/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/pkg/controller/garbagecollector/garbagecollector.go:172 +0xd9
/go/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/test/integration/garbagecollector/garbage_collector_test.go:268 +0xc9
				from junit_3a3d564eebb1750e5c904cc525d117617fc0af51_20171113-090812.xml
```

**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes #55652

**Special notes for your reviewer**:

**Release note**:

```release-note
NONE
```