Clean up flake8 issues before switch

In anticipation of swtiching to flake8 as part of the removal of
pyflakes jobs, clean up a few flake8 errors so that we don't have to
ignore as many things.

Change-Id: Idb8466bb3194904d84e17dd3f2a7c32aff13788c
Merge "Clean up flake8 issues before switch"