const: make block_device_operations const

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index fd5bb8a..2ddf03a 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -2849,7 +2849,7 @@
 	return attached_disk->fops->media_changed(attached_disk);
 }
 
-static struct block_device_operations pktcdvd_ops = {
+static const struct block_device_operations pktcdvd_ops = {
 	.owner =		THIS_MODULE,
 	.open =			pkt_open,
 	.release =		pkt_close,