const: mark struct vm_struct_operations

* mark struct vm_area_struct::vm_ops as const
* mark vm_ops in AGP code

But leave TTM code alone, something is fishy there with global vm_ops
being used.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/video/omap/dispc.c b/drivers/video/omap/dispc.c
index 80a11d0..f16e421 100644
--- a/drivers/video/omap/dispc.c
+++ b/drivers/video/omap/dispc.c
@@ -1035,7 +1035,7 @@
 	atomic_dec(&dispc.map_count[plane]);
 }
 
-static struct vm_operations_struct mmap_user_ops = {
+static const struct vm_operations_struct mmap_user_ops = {
 	.open = mmap_user_open,
 	.close = mmap_user_close,
 };