mm: VM_flags comment fixes

Try to comment away a little of the confusion between mm's vm_area_struct
vm_flags and vmalloc's vm_struct flags: based on an idea by Ulrich Drepper.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/mm.h b/include/linux/mm.h
index fa65160..72a15dc 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -73,7 +73,7 @@
 #endif
 
 /*
- * vm_flags..
+ * vm_flags in vm_area_struct, see mm_types.h.
  */
 #define VM_READ		0x00000001	/* currently active flags */
 #define VM_WRITE	0x00000002