net: dccp : proto: remove Unneeded variable "err"

Fix below issue reported by coccicheck

net/dccp/proto.c:266:5-8: Unneeded variable: "err". Return "0" on line
310
Signed-off-by: Hariprasad Kelam <hariprasad.kelam@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/dccp/proto.c

@@ -263,7 +263,6 @@ int dccp_disconnect(struct sock *sk, int flags)
 	struct inet_connection_sock *icsk = inet_csk(sk);
 	struct inet_sock *inet = inet_sk(sk);
 	struct dccp_sock *dp = dccp_sk(sk);
-	int err = 0;
 	const int old_state = sk->sk_state;
 
 	if (old_state != DCCP_CLOSED)
@@ -307,7 +306,7 @@ int dccp_disconnect(struct sock *sk, int flags)
 	WARN_ON(inet->inet_num && !icsk->icsk_bind_hash);
 
 	sk->sk_error_report(sk);
-	return err;
+	return 0;
 }
 
 EXPORT_SYMBOL_GPL(dccp_disconnect);