[TCP]: Remove num_acked>0 checks from cong.ctrl mods pkts_acked

There is no need for such check in pkts_acked because the
callback is not invoked unless at least one segment got fully
ACKed (i.e., the snd_una moved past skb's end_seq) by the
cumulative ACK's snd_una advancement.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/tcp_bic.c

@@ -210,7 +210,7 @@ static void bictcp_acked(struct sock *sk, u32 cnt, s32 rtt)
 {
 	const struct inet_connection_sock *icsk = inet_csk(sk);
 
-	if (cnt > 0 && icsk->icsk_ca_state == TCP_CA_Open) {
+	if (icsk->icsk_ca_state == TCP_CA_Open) {
 		struct bictcp *ca = inet_csk_ca(sk);
 		cnt -= ca->delayed_ack >> ACK_RATIO_SHIFT;
 		ca->delayed_ack += cnt;

net/ipv4/tcp_cubic.c

@@ -314,7 +314,7 @@ static void bictcp_acked(struct sock *sk, u32 cnt, s32 rtt_us)
 	struct bictcp *ca = inet_csk_ca(sk);
 	u32 delay;
 
-	if (cnt > 0 && icsk->icsk_ca_state == TCP_CA_Open) {
+	if (icsk->icsk_ca_state == TCP_CA_Open) {
 		cnt -= ca->delayed_ack >> ACK_RATIO_SHIFT;
 		ca->delayed_ack += cnt;
 	}