vFile: GC should not remove orphan internal volume

[lipingxue]

Currently, GC removed orphan service and orphan internal volume. It will cause some issue.
For example: two ESX shared 1 datastore, one each ESX, we have a swarm cluster running. When the first swarm cluster create a volume "aaa", an internal volume "_vf_aaa" will be created on the shared datastore. Then for the second swarm cluster, only internal volume "_vf_aaa" is visible, and it think "_vf_aaa" is an orphan volume and try to delete volume "aaa", which is wrong.

So we should remove the code to cleanup orphan internal volume.

[shuklanirdesh82]

mustfix for vFile beta release