Set VM back to its original state if cold migration failed

If migration of a VM in the STOPPED state failed due to
NoValidHost, the VM was erroneously set to ACTIVE.

The fix sets the VM back to its original state instead.

Fix bug 1204905

Change-Id: I67ccac9ff4104fbd63c545b9f9399206a7febae7
Merge "Set VM back to its original state if cold migration failed"