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/s390/block/dasd.c b/drivers/s390/block/dasd.c
index e109da4..dad0449 100644
--- a/drivers/s390/block/dasd.c
+++ b/drivers/s390/block/dasd.c
@@ -2146,7 +2146,7 @@
 	return 0;
 }
 
-struct block_device_operations
+const struct block_device_operations
 dasd_device_operations = {
 	.owner		= THIS_MODULE,
 	.open		= dasd_open,