cleanup: fixed pyflakes errors

Fixed violations detected by jenkins:
http://jenkins.ovirt.org/view/ovirt_engine/job/ovirt_engine_pep8_gerrit/2/violations/?

Change-Id: Iccbe471a023eadc28fc2041c383a6a96eaca5653
Signed-off-by: Sandro Bonazzola <sbonazzo@redhat.com>