[NET_SCHED]: Fix endless loops (part 2): "simple" qdiscs

Convert the "simple" qdiscs to use qdisc_tree_decrease_qlen() where
necessary:

- all graft operations
- destruction of old child qdiscs in prio, red and tbf change operation
- purging of queue in sfq change operation

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 1 deletions

diff --git a/net/sched/sch_cbq.c b/net/sched/sch_cbq.c
index 908b10d0d61f..ba82dfab6043 100644
--- a/net/sched/sch_cbq.c
+++ b/net/sched/sch_cbq.c
@@ -1687,7 +1687,7 @@ static int cbq_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
                 sch_tree_lock(sch);
                 *old = cl->q;
                 cl->q = new;
-                sch->q.qlen -= (*old)->q.qlen;
+                qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
                 qdisc_reset(*old);
                 sch_tree_unlock(sch);