We can use unlock label to unlock ptl and return ret directly to remove
the unneeded out label and reduce the size of mempolicy.o.  No functional
change intended.

[Before]
   text	   data	    bss	    dec	    hex	filename
  26702	   3972	   6168	  36842	   8fea	mm/mempolicy.o

[After]
   text	   data	    bss	    dec	    hex	filename
  26662	   3972	   6168	  36802	   8fc2	mm/mempolicy.o

Link: https://lkml.kernel.org/r/20220719115233.6706-1-linmiaohe@huawei.comSigned-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>