Check for services deleted to break loops in base_services_start

https://bugzilla.redhat.com/show_bug.cgi?id=1600823 shows a
case where systemd throws a service that would usually have been
started out of the boot process *entirely* in order to resolve a
dependency loop. This means the service won't show up as failed,
it will just be inactive when it should be active. This still
should constitute a failure of this test, so let's add a check
for the log message that indicates this situation.

Signed-off-by: Adam Williamson <awilliam@redhat.com>

tests/base_services_start.pm

@@ -21,6 +21,11 @@ sub run {
         assert_script_run "systemctl is-failed mcelog.service";
         record_soft_failure;
     }
+    # "Job foo.service/start deleted to break ordering cycle"-type
+    # message in the log indicates a service got taken out of the boot
+    # process to resolve some kind of dependency loop, see e.g.
+    # https://bugzilla.redhat.com/show_bug.cgi?id=1600823
+    assert_script_run "! journalctl -b | grep 'deleted to break ordering'";
 }