destroy_port fails to delete the port even if the node is locked by the same process.

[Nisha Agarwal]

the method destroy_port() in ironic/db/sqlalchemy/api.py doesnt allow the port to be deleted even if the port belongs to the same node on which it already has the lock. This causes issues for ilo inspection which tries to deletes the port for the NIC which is no longer associated with the node.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/161861

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/161861
Committed: https://git.openstack.org/cgit/openstack/ironic/commit/?id=fdd4216a4fdbd5763bfe2bf506d8f04aaaaadf83
Submitter: Jenkins
Branch: master

commit fdd4216a4fdbd5763bfe2bf506d8f04aaaaadf83
Author: Nisha Agarwal <email address hidden>
Date: Thu Mar 5 09:20:53 2015 -0800

    ironic port deletion fails even if node is locked by same process

    the reservation check at db layer prevents the port to be deleted
    if a process has exclusive lock on the node and is trying to
    delete the port

    Closes-Bug: 1427597

    Change-Id: I36e26b7273c2e12479ed7cd15fc7628f29fd6652