fix subunit2html pep8 issues

trying to fix other parts of the script, but because my emacs is
configured for pep8 inline highlighting I can't start on that until
it stops being lit up like a christmas tree.

Shouldn't have changed any behavior.

Change-Id: I9a65f893f34226525e64a902c50fee9e3d611fc7
Reviewed-on: https://review.openstack.org/20207
Reviewed-by: James E. Blair <corvus@inaugust.com>
Reviewed-by: Clark Boylan <clark.boylan@gmail.com>
Approved: Clark Boylan <clark.boylan@gmail.com>
Tested-by: Jenkins