Remove the first mapping check for vma_link.  Move the mutex_lock into the
braces when vma->vm_file is true.
Signed-off-by: NHuang Shijie <b32955@freescale.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>