net: set tb->fast_sk_family

We need to set the tb->fast_sk_family properly so we can use the proper
comparison function for all subsequent reuseport bind requests.

Fixes: 637bc8bbe6c0 ("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

@@ -328,6 +328,7 @@ success:
 			tb->fastuid = uid;
 			tb->fast_rcv_saddr = sk->sk_rcv_saddr;
 			tb->fast_ipv6_only = ipv6_only_sock(sk);
+			tb->fast_sk_family = sk->sk_family;
 #if IS_ENABLED(CONFIG_IPV6)
 			tb->fast_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
 #endif
@@ -354,6 +355,7 @@ success:
 				tb->fastuid = uid;
 				tb->fast_rcv_saddr = sk->sk_rcv_saddr;
 				tb->fast_ipv6_only = ipv6_only_sock(sk);
+				tb->fast_sk_family = sk->sk_family;
 #if IS_ENABLED(CONFIG_IPV6)
 				tb->fast_v6_rcv_saddr = sk->sk_v6_rcv_saddr;
 #endif