pkt_sched: Fix locking of qdisc_root with qdisc_root_sleeping_lock()

Use qdisc_root_sleeping_lock() instead of qdisc_root_lock() where
appropriate. The only difference is while dev is deactivated, when
currently we can use a sleeping qdisc with the lock of noop_qdisc.
This shouldn't be dangerous since after deactivation root lock could
be used only by gen_estimator code, but looks wrong anyway.

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/sch_cbq.c b/net/sched/sch_cbq.c
index 9b720ad..8b06fa9 100644
--- a/net/sched/sch_cbq.c
+++ b/net/sched/sch_cbq.c
@@ -1754,7 +1754,7 @@
 
 	if (--cl->refcnt == 0) {
 #ifdef CONFIG_NET_CLS_ACT
-		spinlock_t *root_lock = qdisc_root_lock(sch);
+		spinlock_t *root_lock = qdisc_root_sleeping_lock(sch);
 		struct cbq_sched_data *q = qdisc_priv(sch);
 
 		spin_lock_bh(root_lock);