[media] v4l2: make vidioc_s_fbuf const

Write-only ioctls should have a const argument in the ioctl op.
Do this conversion for vidioc_s_fbuf.
Adding const for write-only ioctls was decided during the 2012 Media Workshop.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/platform/omap/omap_vout.c

@@ -1744,7 +1744,7 @@ static int vidioc_streamoff(struct file *file, void *fh, enum v4l2_buf_type i)
 }
 
 static int vidioc_s_fbuf(struct file *file, void *fh,
-				struct v4l2_framebuffer *a)
+				const struct v4l2_framebuffer *a)
 {
 	int enable = 0;
 	struct omap_overlay *ovl;