net_sched: update bstats in dequeue()

Class bytes/packets stats can be misleading because they are updated in
enqueue() while packet might be dropped later.

We already fixed all qdiscs but sch_atm.

This patch makes the final cleanup.

class rate estimators can now match qdisc ones.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/sch_htb.c b/net/sched/sch_htb.c
index acae5b0..9d75b77 100644
--- a/net/sched/sch_htb.c
+++ b/net/sched/sch_htb.c
@@ -574,7 +574,6 @@
 		}
 		return ret;
 	} else {
-		bstats_update(&cl->bstats, skb);
 		htb_activate(q, cl);
 	}
 
@@ -835,6 +834,7 @@
 	} while (cl != start);
 
 	if (likely(skb != NULL)) {
+		bstats_update(&cl->bstats, skb);
 		cl->un.leaf.deficit[level] -= qdisc_pkt_len(skb);
 		if (cl->un.leaf.deficit[level] < 0) {
 			cl->un.leaf.deficit[level] += cl->quantum;