staging/lustre/llite: fix a flag bug of vvp_io_kernel_fault()

After vvp_io_kernel_fault() locked the page, it should set
VM_FAULT_LOCKED.
Signed-off-by: Li Xi <lixi@ddn.com>
Reviewed-on: http://review.whamcloud.com/10740Reviewed-by: Jinshan Xiong <jinshan.xiong@intel.com>
Reviewed-by: Emoly Liu <emoly.liu@intel.com>
Signed-off-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lustre/llite/vvp_io.c

@@ -624,7 +624,7 @@ static int vvp_io_kernel_fault(struct vvp_fault_io *cfio)
 		       page_private(vmf->page), vmf->virtual_address);
 		if (unlikely(!(cfio->fault.ft_flags & VM_FAULT_LOCKED))) {
 			lock_page(vmf->page);
-			cfio->fault.ft_flags &= VM_FAULT_LOCKED;
+			cfio->fault.ft_flags |= VM_FAULT_LOCKED;
 		}
 
 		cfio->ft_vmpage = vmf->page;