staging: unisys: correctly handle return value from queue_delayed_work()

Properly handle the return value from queue_delayed_work() - it's a
bool, not an int, so using a less than comparison isn't appropriate.

This mistake was found by David Binderman <dcb314@hotmail.com>.
Signed-off-by: Benjamin Romer <benjamin.romer@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/unisys/visorbus/periodic_work.c

@@ -86,8 +86,8 @@ bool visor_periodic_work_nextperiod(struct periodic_work *pw)
 		pw->want_to_stop = false;
 		rc = true;  /* yes, true; see visor_periodic_work_stop() */
 		goto unlock;
-	} else if (queue_delayed_work(pw->workqueue, &pw->work,
-				      pw->jiffy_interval) < 0) {
+	} else if (!queue_delayed_work(pw->workqueue, &pw->work,
+				       pw->jiffy_interval)) {
 		pw->is_scheduled = false;
 		rc = false;
 		goto unlock;
@@ -117,8 +117,8 @@ bool visor_periodic_work_start(struct periodic_work *pw)
 		goto unlock;
 	}
 	INIT_DELAYED_WORK(&pw->work, &periodic_work_func);
-	if (queue_delayed_work(pw->workqueue, &pw->work,
-			       pw->jiffy_interval) < 0) {
+	if (!queue_delayed_work(pw->workqueue, &pw->work,
+				pw->jiffy_interval)) {
 		rc = false;
 		goto unlock;
 	}