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/infiniband/hw/ipath/ipath_mmap.c b/drivers/infiniband/hw/ipath/ipath_mmap.c
index fa830e2..b28865f 100644
--- a/drivers/infiniband/hw/ipath/ipath_mmap.c
+++ b/drivers/infiniband/hw/ipath/ipath_mmap.c
@@ -74,7 +74,7 @@
 	kref_put(&ip->ref, ipath_release_mmap_info);
 }
 
-static struct vm_operations_struct ipath_vm_ops = {
+static const struct vm_operations_struct ipath_vm_ops = {
 	.open =     ipath_vma_open,
 	.close =    ipath_vma_close,
 };