mm/migrate.c: cleanup comment for migration_entry_wait()

migration_entry_wait() can also be called from hugetlb_fault() now.
Remove the incorrect comment.

Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com>
Acked-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/migrate.c

@@ -181,8 +181,6 @@ static void remove_migration_ptes(struct page *old, struct page *new)
  * Something used the pte of a page under migration. We need to
  * get to the page and wait until migration is finished.
  * When we return from this function the fault will be retried.
- *
- * This function is called from do_swap_page().
  */
 void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd,
  unsigned long address)