Rename anonymous variable _
Rename anonymous variable _

The usage of the anonymous variable _ confuses the pep8 parser and
causes an error. Renaming it should work around this issue.

Change-Id: Ic1d26de0ca9359456cdaf4c56e58479b9dc1c15a

openstack/dragonflow,openstack/dragonflow,FrankDuan/df_code,FrankDuan/df_code,openstack/dragonflow,FrankDuan/df_code