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/gpu/drm/drm_vm.c b/drivers/gpu/drm/drm_vm.c
index 7e1fbe5..4ac900f 100644
--- a/drivers/gpu/drm/drm_vm.c
+++ b/drivers/gpu/drm/drm_vm.c
@@ -369,28 +369,28 @@
 }
 
 /** AGP virtual memory operations */
-static struct vm_operations_struct drm_vm_ops = {
+static const struct vm_operations_struct drm_vm_ops = {
 	.fault = drm_vm_fault,
 	.open = drm_vm_open,
 	.close = drm_vm_close,
 };
 
 /** Shared virtual memory operations */
-static struct vm_operations_struct drm_vm_shm_ops = {
+static const struct vm_operations_struct drm_vm_shm_ops = {
 	.fault = drm_vm_shm_fault,
 	.open = drm_vm_open,
 	.close = drm_vm_shm_close,
 };
 
 /** DMA virtual memory operations */
-static struct vm_operations_struct drm_vm_dma_ops = {
+static const struct vm_operations_struct drm_vm_dma_ops = {
 	.fault = drm_vm_dma_fault,
 	.open = drm_vm_open,
 	.close = drm_vm_close,
 };
 
 /** Scatter-gather virtual memory operations */
-static struct vm_operations_struct drm_vm_sg_ops = {
+static const struct vm_operations_struct drm_vm_sg_ops = {
 	.fault = drm_vm_sg_fault,
 	.open = drm_vm_open,
 	.close = drm_vm_close,