If register_snap_client fails in atalk_init,
error code should be set, otherwise it will
triggers NULL pointer dereference while unloading
module.
Fixes: 9804501fa122 ("appletalk: Fix potential NULL pointer dereference in unregister_snap_client")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
        ddp_dl = register_snap_client(ddp_snap_id, atalk_rcv);
        if (!ddp_dl) {
                pr_crit("Unable to register DDP with SNAP.\n");
+               rc = -ENOMEM;
                goto out_sock;
        }