Update SolidFire driver to pass newer flake8
Update SolidFire driver to pass newer flake8

Just an easy update of some things that newer versions of
flake8 complains about.

I've updated my env to flake8 2.1.0, and figured might as 
well fix these up rather ignore them.  pep8 is 1.5.6 and pyflakes
is at 0.8.1

Change-Id: I6d22fe95b67acddcece283e6dca6fe980904bfed

Datera/cinder,nexusriot/cinder,phenoxim/cinder,ge0rgi/cinder,Nexenta/cinder,phenoxim/cinder,potsmaster/cinder,nikesh-mahalka/cinder,duhzecca/cinder,openstack/cinder,Hybrid-Cloud/cinder,Paul-Ezell/cinder-1,tlakshman26/cinder-bug-fix-volume-conversion-full,duhzecca/cinder,petrutlucian94/cinder,nikesh-mahalka/cinder,NetApp/cinder,Paul-Ezell/cinder-1,Nexenta/cinder,apporc/cinder,mahak/cinder,manojhirway/ExistingImagesOnNFS,leilihh/cinder,tlakshman26/cinder-new-branch,dims/cinder,takeshineshiro/cinder,cloudbase/cinder,sasukeh/cinder,tlakshman26/cinder-https-changes,takeshineshiro/cinder,petrutlucian94/cinder,scottdangelo/RemoveVolumeMangerLocks,apporc/cinder,mahak/cinder,scality/cinder,manojhirway/ExistingImagesOnNFS,winndows/cinder,tlakshman26/cinder-new-branch,j-griffith/cinder,tlakshman26/cinder-https-changes,winndows/cinder,dims/cinder,bswartz/cinder,tlakshman26/cinder-bug-fix-volume-conversion-full,openstack/cinder,Datera/cinder,potsmaster/cinder,scottdangelo/RemoveVolumeMangerLocks,scality/cinder,leilihh/cinder,NetApp/cinder,cloudbase/cinder,bswartz/cinder,nexusriot/cinder,Hybrid-Cloud/cinder,eharney/cinder,sasukeh/cinder,j-griffith/cinder,eharney/cinder