Comment 4 for bug 1260123

Reviewed: https://review.openstack.org/66403
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=17f27bf1843b0efa89a6b3f507fa47f815fbe3fc
Submitter: Jenkins
Branch: stable/havana

commit 17f27bf1843b0efa89a6b3f507fa47f815fbe3fc
Author: Eric Harney <email address hidden>
Date: Thu Dec 19 16:21:25 2013 -0500

    libvirt: Fix infinite loop waiting for block job

    Libvirt may return an empty dict when a block job has completed.
    In this case, _wait_for_block_job will return True, causing
    its callers to loop.

    Affects volume_snapshot_delete, swap_volume, and live_snapshot.

    (See http://libvirt.org/git/?p=libvirt.git;a=commit;h=0f9e67bf )

    Closes-Bug: #1260123
    Change-Id: Iab81299f0ce32a14e46aee0fd389ed29f7e503b8
    (cherry picked from commit e3ac20fca7494122a4c0ed2edc00377aa92cb49d)