[media] v4l2: add const to argument of write-only s_tuner ioctl

This ioctl is defined as IOW, so pass the argument as const.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Alexey Klimov <klimov.linux@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/usb/em28xx/em28xx-video.c b/drivers/media/usb/em28xx/em28xx-video.c
index af79089..3ef696d 100644
--- a/drivers/media/usb/em28xx/em28xx-video.c
+++ b/drivers/media/usb/em28xx/em28xx-video.c
@@ -1195,7 +1195,7 @@
 }
 
 static int vidioc_s_tuner(struct file *file, void *priv,
-				struct v4l2_tuner *t)
+				const struct v4l2_tuner *t)
 {
 	struct em28xx_fh      *fh  = priv;
 	struct em28xx         *dev = fh->dev;
@@ -1493,7 +1493,7 @@
 }
 
 static int radio_s_tuner(struct file *file, void *priv,
-			 struct v4l2_tuner *t)
+			 const struct v4l2_tuner *t)
 {
 	struct em28xx *dev = ((struct em28xx_fh *)priv)->dev;