Merge pull request #59640 from jianglingxia/jlx-2018020917

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>.

correct the ConstructVolumeSpec func path value

**What this PR does / why we need it**:
the path value is incorrect
**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 #

**Special notes for your reviewer**:

**Release note**:

```release-note
NONE
```

pkg/volume/cephfs/cephfs.go

@@ -173,7 +173,7 @@ func (plugin *cephfsPlugin) ConstructVolumeSpec(volumeName, mountPath string) (*
 		VolumeSource: v1.VolumeSource{
 			CephFS: &v1.CephFSVolumeSource{
 				Monitors: []string{},
-				Path:     volumeName,
+				Path:     mountPath,
 			},
 		},
 	}