The current release of flake8-logging-format enforces G002 "Logging
statement uses '%'", so don't do that.
Also disable G200 ("Logging statement uses exception in arguments")
to be consistent with cinder.
Also, restore the pep8 job to voting status.
Change-Id: Ia4d40a85ac150b13575e98eb16e2607c5228b2f6