media: cx231xx: make cx231xx_vbi_qops const

Make this const as it is only passed to the const argument of the
function videobuf_queue_vmalloc_init in the file referencing it.
Also, make the declaration in the header const.

Structure found using Coccienlle and changes done by hand.
Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/usb/cx231xx/cx231xx-vbi.c

@@ -285,7 +285,7 @@ static void vbi_buffer_release(struct videobuf_queue *vq,
 	free_buffer(vq, buf);
 }
 
-struct videobuf_queue_ops cx231xx_vbi_qops = {
+const struct videobuf_queue_ops cx231xx_vbi_qops = {
 	.buf_setup   = vbi_buffer_setup,
 	.buf_prepare = vbi_buffer_prepare,
 	.buf_queue   = vbi_buffer_queue,

drivers/media/usb/cx231xx/cx231xx-vbi.h

@@ -22,7 +22,7 @@
 #ifndef _CX231XX_VBI_H
 #define _CX231XX_VBI_H
 
-extern struct videobuf_queue_ops cx231xx_vbi_qops;
+extern const struct videobuf_queue_ops cx231xx_vbi_qops;
 
 #define   NTSC_VBI_START_LINE 10	/* line 10 - 21 */
 #define   NTSC_VBI_END_LINE   21