inet6: Clean up failure path in do_ipv6_setsockopt().

We can reuse the unlock label above and need not repeat the same code.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv6/ipv6_sockglue.c

@@ -1005,10 +1005,8 @@ int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
 	return retv;
 
 e_inval:
-	sockopt_release_sock(sk);
-	if (needs_rtnl)
-		rtnl_unlock();
-	return -EINVAL;
+	retv = -EINVAL;
+	goto unlock;
 }
 
 int ipv6_setsockopt(struct sock *sk, int level, int optname, sockptr_t optval,