nds32: fix logic for module

This bug is report by Dan Carpenter. We shall use ~loc_mask instead of
!loc_mask because we need to and(&) the bits of ~loc_mask.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: c9a4a8da ("nds32: Loadable modules")
Signed-off-by: Greentime Hu <greentime@andestech.com>