Comment 10 for bug 1750618

Reviewed: https://review.openstack.org/550545
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=3c5e519a8875a9766a0d3a06cb76cceba26634e6
Submitter: Zuul
Branch: stable/queens

commit 3c5e519a8875a9766a0d3a06cb76cceba26634e6
Author: Matt Riedemann <email address hidden>
Date: Tue Feb 20 13:48:12 2018 -0500

    Only attempt a rebuild claim for an evacuation to a new host

    Change I11746d1ea996a0f18b7c54b4c9c21df58cc4714b changed the
    behavior of the API and conductor when rebuilding an instance
    with a new image such that the image is run through the scheduler
    filters again to see if it will work on the existing host that
    the instance is running on.

    As a result, conductor started passing 'scheduled_node' to the
    compute which was using it for logic to tell if a claim should be
    attempted. We don't need to do a claim for a rebuild since we're
    on the same host.

    This removes the scheduled_node logic from the claim code, as we
    should only ever attempt a claim if we're evacuating, which we
    can determine based on the 'recreate' parameter.

    Change-Id: I7fde8ce9dea16679e76b0cb2db1427aeeec0c222
    Closes-Bug: #1750618
    (cherry picked from commit a39029076c7997236a7f999682fb1e998c474204)