mptcp: Paulo's fix for #443

Signed-off-by: Christoph Paasch <cpaasch@apple.com>

Author: cpaasch

net/mptcp/protocol.c

@@ -2758,6 +2758,8 @@ static void __mptcp_init_sock(struct sock *sk)
 	msk->rmem_fwd_alloc = 0;
 	WRITE_ONCE(msk->rmem_released, 0);
 	msk->timer_ival = TCP_RTO_MIN;
+	msk->scaling_ratio = (1200 << TCP_RMEM_TO_WIN_SCALE) /
+			     SKB_TRUESIZE(4096);
 
 	WRITE_ONCE(msk->first, NULL);
 	inet_csk(sk)->icsk_sync_mss = mptcp_sync_mss;