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/arch/powerpc/sysdev/axonram.c b/arch/powerpc/sysdev/axonram.c
index a477991..88f4ae7 100644
--- a/arch/powerpc/sysdev/axonram.c
+++ b/arch/powerpc/sysdev/axonram.c
@@ -165,7 +165,7 @@
 	return 0;
 }
 
-static struct block_device_operations axon_ram_devops = {
+static const struct block_device_operations axon_ram_devops = {
 	.owner		= THIS_MODULE,
 	.direct_access	= axon_ram_direct_access
 };