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/ub.c b/drivers/block/ub.c
index cc54473..c739b20 100644
--- a/drivers/block/ub.c
+++ b/drivers/block/ub.c
@@ -1789,7 +1789,7 @@
 	return lun->changed;
 }
 
-static struct block_device_operations ub_bd_fops = {
+static const struct block_device_operations ub_bd_fops = {
 	.owner		= THIS_MODULE,
 	.open		= ub_bd_open,
 	.release	= ub_bd_release,