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_netem.c b/net/sched/sch_netem.c
index fb0294d..3781e55 100644
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -341,7 +341,7 @@
 	for (i = 0; i < n; i++)
 		d->table[i] = data[i];
 
-	root_lock = qdisc_root_lock(sch);
+	root_lock = qdisc_root_sleeping_lock(sch);
 
 	spin_lock_bh(root_lock);
 	d = xchg(&q->delay_dist, d);