Patch in cisco unit test not being correctly cleared by stopall

[Kevin Benton]

A recent patch removed the explicit patch stops from most of the unit tests to let the default mock.patch.stopall handle the cleanup[1]. However, there appears to be cases where stopall loses the reference to a patch and doesn't stop it correctly. In this particular case, the nexus test patch to sys.modules is not being stopped correctly so it's causing unit test failures in the gate[2].

1. https://github.com/openstack/neutron/commit/6546ba570367aba7209ec36544ec4cf742e0bd63
2. http://logs.openstack.org/10/86810/5/check/gate-neutron-python27/89dfa5c/testr_results.html.gz

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/87097

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/87097
Committed: https://git.openstack.org/cgit/openstack/neutron/commit/?id=e7ca2541b13d9e755f443b866708865ac22a8bd1
Submitter: Jenkins
Branch: master

commit e7ca2541b13d9e755f443b866708865ac22a8bd1
Author: Kevin Benton <email address hidden>
Date: Sat Apr 12 21:27:36 2014 +0000

    Fix dangling patches in Cisco and Midonet tests

    Cisco Nexus Tests:
    Explicitly stops the patch to sys.modules immediately
    after use to fix sporadic failures caused by the patch
    not being handled correctly by mock.patch.stopall.

    Midonet Interface Test:
    Removes the double-patch of the 'device_exists' method
    in ip_lib.

    Closes-Bug: #1307025
    Closes-Bug: #1307038
    Change-Id: Ie22505bb8e406a61e40819d60c76d229916a6e01