[NETFILTER]: nfnetlink_queue: fix EPERM when binding/unbinding and instance 0 exists

Similar to the nfnetlink_log problem, nfnetlink_queue incorrectly
returns -EPERM when binding or unbinding to an address family and
queueing instance 0 exists and is owned by a different process. Unlike
nfnetlink_log it previously completes the operation, but it is still
incorrect.
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/netfilter/nfnetlink_queue.c

@@ -703,19 +703,12 @@ nfqnl_recv_config(struct sock *ctnl, struct sk_buff *skb,
 		/* Commands without queue context - might sleep */
 		switch (cmd->command) {
 		case NFQNL_CFG_CMD_PF_BIND:
-			ret = nf_register_queue_handler(ntohs(cmd->pf),
-							&nfqh);
-			break;
+			return nf_register_queue_handler(ntohs(cmd->pf),
+							 &nfqh);
 		case NFQNL_CFG_CMD_PF_UNBIND:
-			ret = nf_unregister_queue_handler(ntohs(cmd->pf),
-							  &nfqh);
-			break;
-		default:
-			break;
+			return nf_unregister_queue_handler(ntohs(cmd->pf),
+							   &nfqh);
 		}
-
-		if (ret < 0)
-			return ret;
 	}
 
 	rcu_read_lock();