Input: polled device - do not start polling if interval is zero

If the poll interval is set to 0 via new sysfs entry and device is
opened after that, polling is started with interval 0. This causes
huge CPU load. Same happens if the rate was 0 when the device was
closed and then reopened.
Signed-off-by: Samu Onkalo <samu.p.onkalo@nokia.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

drivers/input/input-polldev.c

@@ -88,7 +88,9 @@ static int input_open_polled_device(struct input_dev *input)
 	if (dev->open)
 		dev->open(dev);
 
-	queue_delayed_work(polldev_wq, &dev->work, 0);
+	/* Only start polling if polling is enabled */
+	if (dev->poll_interval > 0)
+		queue_delayed_work(polldev_wq, &dev->work, 0);
 
 	return 0;
 }