Updated openstack/openstack
Project: openstack/cinder  cef588d2d13a829e0699215cef2c572237321c4a

Amend unused variables to assist pylint testing

Amedning unused variables with a prefix of an underscore to prevent them
being picked up in pylint testing, consistency, and for general housekeeping.
Change to pylintrc also required to enforce the rule.

Closes-bug #1268062

Change-Id: I80c2cbdc52d6f37823fae90d0096836166412643