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>

kernel/perf_event.c

@@ -2253,7 +2253,7 @@ static void perf_mmap_close(struct vm_area_struct *vma)
 	}
 }
 
-static struct vm_operations_struct perf_mmap_vmops = {
+static const struct vm_operations_struct perf_mmap_vmops = {
 	.open		= perf_mmap_open,
 	.close		= perf_mmap_close,
 	.fault		= perf_mmap_fault,

kernel/relay.c

@@ -60,7 +60,7 @@ static int relay_buf_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 /*
  * vm_ops for relay file mappings.
  */
-static struct vm_operations_struct relay_file_mmap_ops = {
+static const struct vm_operations_struct relay_file_mmap_ops = {
 	.fault = relay_buf_fault,
 	.close = relay_file_mmap_close,
 };