Updated openstack/openstack
Project: openstack/neutron  1859a5ae0056cd4b837005b02b80c542321fe1cc

OVS lib defer apply doesn't handle concurrency

The OVS lib deferred apply methods use a dict to save flows to add,
modify or delete when deffered apply is switched off.
If another thread adds, modifies or deletes flows on that dict during
another process called deffered_apply_off, its flows could be ignored.

This fix stash reference flows list and point the flows list to a new
cleared flows list. Then, it applies flows from the stashed flows list.

Closes-bug: #1263866
(cherry picked from commit 501213686886baccd3280e10b8856a25d3517519)

Conflicts:
	neutron/tests/unit/agent/linux/test_ovs_lib.py

Change-Id: I3b22c7ec055934d7f30067924c7a7fd71b2f6081