tcp: do not clear packets_out in tcp_create_openreq_child()

New sockets have this field cleared, and tcp_disconnect()
calls tcp_write_queue_purge() which among other things
also clear tp->packets_out

So a listener is guaranteed to have this field cleared.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/ipv4/tcp_minisocks.c

@@ -484,7 +484,6 @@ struct sock *tcp_create_openreq_child(const struct sock *sk,
 	minmax_reset(&newtp->rtt_min, tcp_jiffies32, ~0U);
 	newicsk->icsk_ack.lrcvtime = tcp_jiffies32;
 
-	newtp->packets_out = 0;
 	newtp->retrans_out = 0;
 	newtp->sacked_out = 0;
 	newtp->tlp_high_seq = 0;