VMware: fix rescue/unrescue instance

Fixes bug 1199955

The problem is due to the way in which the VM's are named on vCenter.
That is, in Nova a VM has a name and a UUID. In vCenter the VM only
has a name. The VM name on vCenter is Nova's instance UUID. When the
rescue/unrescue operation takes place a new VM is spawned/destroyed.
The Nova VM has the name '<name>-rescue'. The problem is that the
new rescue name was not passed correctly to the vCenter, that is,
it should have been '<uuid>-rescue' but it was just '<uuid>'. This
caused the opertaion to fail as there is already a VM with that name
on vCenter. A new name should have been passed which is '<uuid>-rescue'.

Change-Id: Icfe6e5021b29026788bec8f3526f94a8ec0a65e2
Merge "VMware: fix rescue/unrescue instance"