scftorture: Shut down if nonsensical arguments given

If (say) a 10-hour scftorture run is started, but the module parameters
are so nonsensical that the run doesn't even start, then scftorture will
wait the full ten hours when run built into a guest OS.  This commit
therefore shuts down the system in this case so that the error is reported
immediately instead of ten hours hence.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

kernel/scftorture.c

@@ -651,6 +651,10 @@ static int __init scf_torture_init(void)
 unwind:
 	torture_init_end();
 	scf_torture_cleanup();
+	if (shutdown_secs) {
+		WARN_ON(!IS_MODULE(CONFIG_SCF_TORTURE_TEST));
+		kernel_power_off();
+	}
 	return firsterr;
 }