In gfs2_rbm_find, rs is always NULL when minext is NULL, so
gfs2_reservation_check_and_update will never be called on a NULL minext.
This isn't innediately obvious though, so also check for a NULL minext
for better code readability.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
                        goto next_bitmap;
                }
                rbm->offset = offset;
-               if (!rs)
+               if (!rs || !minext)
                        return 0;
 
                ret = gfs2_reservation_check_and_update(rbm, rs, *minext,