When the virt module returns success for the shutdown state, it
has only sucessfully sent the signal to shut down. It may still
take a few more minutes for the VM's to actually complete their
shut down. If we try to change the image while the machine is
still busy shutting down, the image conversion/compression fails
and the resulting state is incomplete.
In this patch we do the following:
1. Find and shut down the running VM's without needing to look
at the inventory. This reduces complexity in the play.
2. Makes sure that the VM's are all in the 'shut off' state,
before continuing on to saving the images.
Change-Id: Icf337447f7a9b4033af261910f77216a170937ed
9b0f2b5dbd