deallocate_fixed_ip should handle exception to rollback quota

[jichenjc]

in nova-network, deallocate_fixed_ip function reserve quota first then do deallocate operations
if any operation failed, the quota reserve operation need to be rollback

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/76413

[Sean Dague (sdague)]

patch is still active (last updated 2 days ago)

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/76413
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=635c5b611ae765bca3a888b1fcabe6bf0027c948
Submitter: Jenkins
Branch: master

commit 635c5b611ae765bca3a888b1fcabe6bf0027c948
Author: jichenjc <email address hidden>
Date: Tue Feb 25 22:09:55 2014 +0800

    Add Quota roll back for deallocate fix ip in nova-network

    in nova-network, deallocate_fixed_ip function reserve quota
    first then do deallocate operations if any operation failed,
    the quota reserve operation need to be rollback.

    Change-Id: If57d2b8a24b2f6ed3d90a1357e89782194df013c
    Closes-Bug: #1284930