[media] radio-shark*: Call cancel_work_sync from disconnect rather then release

This removes the need for shark_led_work to take the v4l2 lock.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/radio/radio-shark.c b/drivers/media/radio/radio-shark.c
index e35b8d9..1d76afa 100644
--- a/drivers/media/radio/radio-shark.c
+++ b/drivers/media/radio/radio-shark.c
@@ -181,14 +181,6 @@
 		container_of(work, struct shark_device, led_work);
 	int i, res, brightness, actual_len;
 
-	/*
-	 * We use the v4l2_dev lock and registered bit to ensure the device
-	 * does not get unplugged and unreffed while we're running.
-	 */
-	mutex_lock(&shark->tea.mutex);
-	if (!video_is_registered(&shark->tea.vd))
-		goto leave;
-
 	for (i = 0; i < 3; i++) {
 		if (!test_and_clear_bit(i, &shark->brightness_new))
 			continue;
@@ -208,8 +200,6 @@
 			v4l2_err(&shark->v4l2_dev, "set LED %s error: %d\n",
 				 shark->led_names[i], res);
 	}
-leave:
-	mutex_unlock(&shark->tea.mutex);
 }
 
 static void shark_led_set_blue(struct led_classdev *led_cdev,
@@ -259,6 +249,8 @@
 	for (i = 0; i < NO_LEDS; i++)
 		led_classdev_unregister(&shark->leds[i]);
 
+	cancel_work_sync(&shark->led_work);
+
 	v4l2_device_put(&shark->v4l2_dev);
 }
 
@@ -266,7 +258,6 @@
 {
 	struct shark_device *shark = v4l2_dev_to_shark(v4l2_dev);
 
-	cancel_work_sync(&shark->led_work);
 	v4l2_device_unregister(&shark->v4l2_dev);
 	kfree(shark->transfer_buffer);
 	kfree(shark);