netfilter: nfnetlink_log: just returns error for unknown command

This patch stops processing options for unknown command.
Signed-off-by: NKen-ichirou MATSUZAWA <chamas@h4.dion.ne.jp>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nfnetlink_log.c

@@ -888,7 +888,7 @@ static int nfulnl_recv_config(struct net *net, struct sock *ctnl,
 			goto out_put;
 		default:
 			ret = -ENOTSUPP;
-			break;
+			goto out_put;
 		}
 	} else if (!inst) {
 		ret = -ENODEV;