V4L/DVB: bt819: cleanup v4l2_subdev_notify() parameters

The 3rd parameter v4l2_subdev_notify() is passed to the notify() callback
which is a pointer, see <media/v4l2-subdev.h> and <media/v4l2-device.h>.

This will remove the following sparse warning (see "make C=1"):
 * Using plain integer as NULL pointer
Signed-off-by: Márton Németh <nm127@freemail.hu>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/bt819.c

@@ -254,7 +254,7 @@ static int bt819_s_std(struct v4l2_subdev *sd, v4l2_std_id std)
 		v4l2_err(sd, "no notify found!\n");
 
 	if (std & V4L2_STD_NTSC) {
-		v4l2_subdev_notify(sd, BT819_FIFO_RESET_LOW, 0);
+		v4l2_subdev_notify(sd, BT819_FIFO_RESET_LOW, NULL);
 		bt819_setbit(decoder, 0x01, 0, 1);
 		bt819_setbit(decoder, 0x01, 1, 0);
 		bt819_setbit(decoder, 0x01, 5, 0);
@@ -263,7 +263,7 @@ static int bt819_s_std(struct v4l2_subdev *sd, v4l2_std_id std)
 		/* bt819_setbit(decoder, 0x1a,  5, 1); */
 		timing = &timing_data[1];
 	} else if (std & V4L2_STD_PAL) {
-		v4l2_subdev_notify(sd, BT819_FIFO_RESET_LOW, 0);
+		v4l2_subdev_notify(sd, BT819_FIFO_RESET_LOW, NULL);
 		bt819_setbit(decoder, 0x01, 0, 1);
 		bt819_setbit(decoder, 0x01, 1, 1);
 		bt819_setbit(decoder, 0x01, 5, 1);
@@ -288,7 +288,7 @@ static int bt819_s_std(struct v4l2_subdev *sd, v4l2_std_id std)
 	bt819_write(decoder, 0x08, (timing->hscale >> 8) & 0xff);
 	bt819_write(decoder, 0x09, timing->hscale & 0xff);
 	decoder->norm = std;
-	v4l2_subdev_notify(sd, BT819_FIFO_RESET_HIGH, 0);
+	v4l2_subdev_notify(sd, BT819_FIFO_RESET_HIGH, NULL);
 	return 0;
 }
 
@@ -306,7 +306,7 @@ static int bt819_s_routing(struct v4l2_subdev *sd,
 		v4l2_err(sd, "no notify found!\n");
 
 	if (decoder->input != input) {
-		v4l2_subdev_notify(sd, BT819_FIFO_RESET_LOW, 0);
+		v4l2_subdev_notify(sd, BT819_FIFO_RESET_LOW, NULL);
 		decoder->input = input;
 		/* select mode */
 		if (decoder->input == 0) {
@@ -316,7 +316,7 @@ static int bt819_s_routing(struct v4l2_subdev *sd,
 			bt819_setbit(decoder, 0x0b, 6, 1);
 			bt819_setbit(decoder, 0x1a, 1, 0);
 		}
-		v4l2_subdev_notify(sd, BT819_FIFO_RESET_HIGH, 0);
+		v4l2_subdev_notify(sd, BT819_FIFO_RESET_HIGH, NULL);
 	}
 	return 0;
 }