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/sound/usb/usx2y/usx2yhwdeppcm.c b/sound/usb/usx2y/usx2yhwdeppcm.c
index 117946f..4b2304c 100644
--- a/sound/usb/usx2y/usx2yhwdeppcm.c
+++ b/sound/usb/usx2y/usx2yhwdeppcm.c
@@ -697,7 +697,7 @@
 }
 
 
-static struct vm_operations_struct snd_usX2Y_hwdep_pcm_vm_ops = {
+static const struct vm_operations_struct snd_usX2Y_hwdep_pcm_vm_ops = {
 	.open = snd_usX2Y_hwdep_pcm_vm_open,
 	.close = snd_usX2Y_hwdep_pcm_vm_close,
 	.fault = snd_usX2Y_hwdep_pcm_vm_fault,