net: use inet6_rcv_saddr to compare sockets

In ipv6_rcv_saddr_equal() we need to use inet6_rcv_saddr(sk) for the
ipv6 compare with the fast socket information to make sure we're doing
the proper comparisons.

Fixes: 637bc8bb ("inet: reset tb->fastreuseport when adding a reuseport sk")
Reported-and-tested-by: Cole Robinson <crobinso@redhat.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/inet_connection_sock.c

@@ -266,7 +266,7 @@ static inline int sk_reuseport_match(struct inet_bind_bucket *tb,
 #if IS_ENABLED(CONFIG_IPV6)
 	if (tb->fast_sk_family == AF_INET6)
 		return ipv6_rcv_saddr_equal(&tb->fast_v6_rcv_saddr,
-					    &sk->sk_v6_rcv_saddr,
+					    inet6_rcv_saddr(sk),
 					    tb->fast_rcv_saddr,
 					    sk->sk_rcv_saddr,
 					    tb->fast_ipv6_only,