pkt_sched: Update drops stats in act_police

Action police statistics could be misleading because drops are not
shown when expected.

With feedback from: Jamal Hadi Salim <hadi@cyberus.ca>

Reported-by: Pawel Staszewski <pstaszewski@itcare.pl>
Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Acked-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched/act_police.c

@@ -294,6 +294,8 @@ static int tcf_act_police(struct sk_buff *skb, struct tc_action *a,
 	if (police->tcfp_ewma_rate &&
 	    police->tcf_rate_est.bps >= police->tcfp_ewma_rate) {
 		police->tcf_qstats.overlimits++;
+		if (police->tcf_action == TC_ACT_SHOT)
+			police->tcf_qstats.drops++;
 		spin_unlock(&police->tcf_lock);
 		return police->tcf_action;
 	}
@@ -327,6 +329,8 @@ static int tcf_act_police(struct sk_buff *skb, struct tc_action *a,
 	}
 
 	police->tcf_qstats.overlimits++;
+	if (police->tcf_action == TC_ACT_SHOT)
+		police->tcf_qstats.drops++;
 	spin_unlock(&police->tcf_lock);
 	return police->tcf_action;
 }