The CSI mounter creates the following paths during SetUp():
* .../pods/<podID>/volumes/kubernetes.io~csi/<specVolId>/mount/
* .../pods/<podID>/volumes/kubernetes.io~csi/<specVolId>/volume_data.json
During TearDown(), it does not remove the `.../kubernetes.io~csi/<specVolId>/`
directory, leaving behind orphan volumes: method cleanupOrphanedPodDirs()
complains with 'Orphaned pod found, but volume paths are still present
on disk'.
Fix that by removing the above directory in removeMountDir().
Signed-off-by: Ilias Tsitsimpis <iliastsi@arrikto.com>
6590c3fe35