Comment 1 for bug 1395731

Reviewed: https://review.openstack.org/136782
Committed: https://git.openstack.org/cgit/stackforge/powervc-driver/commit/?id=e506e9a9b46950efab9a6a82e228d5d71c804d11
Submitter: Jenkins
Branch: master

commit e506e9a9b46950efab9a6a82e228d5d71c804d11
Author: terryyao <email address hidden>
Date: Mon Nov 24 23:02:33 2014 +0800

    Clear pvc_id during instance spawn failing

    1. In powevc nova driver, it's better to use instance.save() instead of
    db call

    2. clear pvc_id after destory the powervc instance.

    3. override pvc_id regardless powervc instance's metadata pvc_id.

    Closes-Bug: #1395731
    Change-Id: I2bb2494a8a2976064494101af811f6be22379472