[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>
diff --git a/drivers/media/platform/fsl-viu.c b/drivers/media/platform/fsl-viu.c
index 20f9810..897250b 100644
--- a/drivers/media/platform/fsl-viu.c
+++ b/drivers/media/platform/fsl-viu.c
@@ -860,7 +860,7 @@
 	return 0;
 }
 
-int vidioc_s_fbuf(struct file *file, void *priv, struct v4l2_framebuffer *arg)
+int vidioc_s_fbuf(struct file *file, void *priv, const struct v4l2_framebuffer *arg)
 {
 	struct viu_fh  *fh = priv;
 	struct viu_dev *dev = fh->dev;