pkt_sched: Fix qstats.qlen updating in dump_stats

Some classful qdiscs miss qstats.qlen updating with q.qlen of their
child qdiscs in dump_stats methods.

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/sch_drr.c b/net/sched/sch_drr.c
index 12b2fb0..5a888af 100644
--- a/net/sched/sch_drr.c
+++ b/net/sched/sch_drr.c
@@ -274,8 +274,10 @@
 	struct tc_drr_stats xstats;
 
 	memset(&xstats, 0, sizeof(xstats));
-	if (cl->qdisc->q.qlen)
+	if (cl->qdisc->q.qlen) {
 		xstats.deficit = cl->deficit;
+		cl->qdisc->qstats.qlen = cl->qdisc->q.qlen;
+	}
 
 	if (gnet_stats_copy_basic(d, &cl->bstats) < 0 ||
 	    gnet_stats_copy_rate_est(d, &cl->rate_est) < 0 ||