inet: Fix missing return value in inet6_hash

As part of a series to implement faster SO_REUSEPORT lookups,
commit 086c653f ("sock: struct proto hash function may error")
added return values to protocol hash functions and
commit 496611d7 ("inet: create IPv6-equivalent inet_hash function")
implemented a new hash function for IPv6.  However, the latter does
not respect the former's convention.

This properly propagates the hash errors in the IPv6 case.

Fixes: 496611d7 ("inet: create IPv6-equivalent inet_hash function")
Reported-by: NSoheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: NCraig Gallek <kraig@google.com>
Acked-by: NSoheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv6/inet6_hashtables.c

@@ -264,13 +264,15 @@ EXPORT_SYMBOL_GPL(inet6_hash_connect);
 
 int inet6_hash(struct sock *sk)
 {
+	int err = 0;
+
 	if (sk->sk_state != TCP_CLOSE) {
 		local_bh_disable();
-		__inet_hash(sk, NULL, ipv6_rcv_saddr_equal);
+		err = __inet_hash(sk, NULL, ipv6_rcv_saddr_equal);
 		local_bh_enable();
 	}
 
-	return 0;
+	return err;
 }
 EXPORT_SYMBOL_GPL(inet6_hash);