If there were no sudo failures on the host, the pre-check was
failing because the exit code of grep was propogating.
Change-Id: I0c9cce65cb6f9109cfc2bbf5b8fe8da15cb8ff88
Reviewed-on: https://review.openstack.org/12448
Reviewed-by: Clark Boylan <clark.boylan@gmail.com>
Approved: James E. Blair <corvus@inaugust.com>
Tested-by: Jenkins