Comment 8 for bug 1713796

Reviewed: https://review.openstack.org/507197
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=a2e0bfdea8b36755e01e210f11f206f436e8d8ec
Submitter: Jenkins
Branch: stable/pike

commit a2e0bfdea8b36755e01e210f11f206f436e8d8ec
Author: Matt Riedemann <email address hidden>
Date: Thu Sep 21 22:25:53 2017 -0400

    Remove allocations when unshelve fails on host

    When we unshelve an offloaded instance, the scheduler
    creates allocations in placement when picking a host.

    If the unshelve fails on the host, due to either the
    instance claim failing or the guest spawn failing, we
    need to remove the allocations since the instance isn't
    actually running on that host.

    Change-Id: Id2c7b7b3b4abda8a3b878fdee6806bcfe096e12e
    Closes-Bug: #1713796
    (cherry picked from commit f18202185d05e3f7e89fca6bbc17daf3c5dc4b98)