mm/ksm.c: update get_user_pages() argument in comment

This updates get_user_pages()'s argument in ksm_test_exit()'s comment
Signed-off-by: Li Chen <chenli@uniontech.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/30ac2417-f1c7-f337-0beb-df561295298c@uniontech.comSigned-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/ksm.c

@@ -455,7 +455,7 @@ static inline bool ksm_test_exit(struct mm_struct *mm)
 /*
  * We use break_ksm to break COW on a ksm page: it's a stripped down
  *
- *	if (get_user_pages(addr, 1, 1, 1, &page, NULL) == 1)
+ *	if (get_user_pages(addr, 1, FOLL_WRITE, &page, NULL) == 1)
  *		put_page(page);
  *
  * but taking great care only to touch a ksm page, in a VM_MERGEABLE vma,