VMware ESX: Boot from volume must not relocate vol

ESX does not support relocate API. Moreover when working with ESX the boot
from volume logic need not perform relocation since the volume's datastore
is always visible to the ESX host.

The fix is to ignore relocation when working with ESX.

Change-Id: I227cf2ea5b6f681150ede0bf6257eb238f1452d2
Closes-bug: #1244918
Merge "VMware ESX: Boot from volume must not relocate vol"