VMware: bug fix for VM rescue when config drive is configured

The addition of the config drive feature broke the VM rescue. The
cause of the problem was setting the instance UUID to the name of
the rescue instance. This must be a UUID! The solution
is to pass the instance name to the spawn method instead of writing
this on the instance UUID.

Change-Id: Ia8494b0c8099753b666bda18a19c4c9a3f764616
Closes-bug: #1247427
Merge "VMware: bug fix for VM rescue when config drive is configured"