VMware: rescue with image that is not linked clone leaves rescue vmdk in the instance folder

[Gary Kotton]

A rescue of an image that is not linked clone will leave the rescue image disk in the original VM folder. The disk will not be cleaned up properly.
This leads to a number of problems:
1. usage of unnecessary disk space
2. additional rescues for the same VM may fail

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/80929

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/80929
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=cfdd9441b1545b5d89be6e8bca036ba185099f12
Submitter: Jenkins
Branch: master

commit cfdd9441b1545b5d89be6e8bca036ba185099f12
Author: Gary Kotton <email address hidden>
Date: Mon Mar 17 01:54:58 2014 -0700

    VMware: fix rescue disk location when image is not linked clone

    A rescue of a VM that has an image which is not linked clone would
    create the rescue disk in the original VM's folder and not in the
    rescue VM's folder. When the unrescue takes place the rescue disk
    will not be deleted.

    The patch adds unit tests that validates that the rescue disk location
    is correct.

    Change-Id: I17dfcade0a162057219bc6d108987bec53f526f9
    Co-authored-by: Vui Lam<email address hidden>
    Closes-bug: #1293435