tests: fix spurious regression test failures

Change-Id: I752aeb8e25f43281d2f5cf33d0ff5aeae49687e7
BUG: 764966
Signed-off-by: Jeff Darcy <jdarcy@redhat.com>
Reviewed-on: http://review.gluster.org/4794
Reviewed-by: Anand Avati <avati@redhat.com>
Tested-by: Anand Avati <avati@redhat.com>