Bandwidth usage object not created after db update

[Andrew Laski]

When using objects.BandwidthUsage().create() it was updating the database and then trying to populate the object with the returned result. But db.bw_usage_update does not return a result so the object creation fails.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/172524

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/172524
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=adbc0f1e550ec9dd63e87c2e89ac18141470a0e6
Submitter: Jenkins
Branch: master

commit adbc0f1e550ec9dd63e87c2e89ac18141470a0e6
Author: Andrew Laski <email address hidden>
Date: Fri Apr 10 13:59:14 2015 -0400

    Return bandwidth usage after updating

    When using objects.BandwidthUsage().create() it was updating the
    database and then trying to populate the object with the returned
    result. But db.bw_usage_update() does not return a result so the object
    creation fails.

    Change-Id: I18fe2627ef2f998a407eef0b8e6649e21ced252c
    Closes-Bug: 1442749