CA-209507: Clean up VGPU.scheduled_to_be_resident_on if VM.start fails
CA-209507: Clean up VGPU.scheduled_to_be_resident_on if VM.start fails

Without this, the VGPU will be (incorrectly) accounted for in PGPU free
space calculations, even though the VM is not running or starting up.

Signed-off-by: John Else <37b74501daa612e48fea94f9846ed4ddeb6a8f07@citrix.com>

jjd27/xen-api,jjd27/xen-api,jjd27/xen-api,jjd27/xen-api,jjd27/xen-api,jjd27/xen-api