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/scsi/sg.c b/drivers/scsi/sg.c
index 848b594..0cb049f 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -1185,7 +1185,7 @@
 	return VM_FAULT_SIGBUS;
 }
 
-static struct vm_operations_struct sg_mmap_vm_ops = {
+static const struct vm_operations_struct sg_mmap_vm_ops = {
 	.fault = sg_vma_fault,
 };