Automatic merge from submit-queue (batch tested with PRs 44469, 44566, 44467, 44526)

Kubelet:rkt Fix the hostPath Volume creation

**What this PR does / why we need it**:

This PR fix the `hostPath` volume when the path exist and it's not a directory.
At the moment, the creation of a `hostPath` volume for an existing file leads to this error:

> kubelet[1984]: E0413 07:53:16.480922    1984 pod_workers.go:184] Error syncing pod 38359a57-1fb1-11e7-a484-76870fe7db83, skipping: failed to SyncPod: mkdir /usr/share/coreos/lsb-release: not a directory

**Special notes for your reviewer**:

You can have a look to the difference with this [gist](https://gist.github.com/JulienBalestra/28ae15efc8a1393d350300880c07ff4f)