V4L/DVB (13377): make struct videobuf_queue_ops constant

The videobuf_queue_ops function vector is not declared constant, but
there's no need for the videobuf layer to ever change it.  Make it const
so that videobuf users can make their operations const without warnings.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/videobuf-dma-contig.c b/drivers/media/video/videobuf-dma-contig.c
index c3065c4..d25f284 100644
--- a/drivers/media/video/videobuf-dma-contig.c
+++ b/drivers/media/video/videobuf-dma-contig.c
@@ -429,7 +429,7 @@
 };
 
 void videobuf_queue_dma_contig_init(struct videobuf_queue *q,
-				    struct videobuf_queue_ops *ops,
+				    const struct videobuf_queue_ops *ops,
 				    struct device *dev,
 				    spinlock_t *irqlock,
 				    enum v4l2_buf_type type,