[NET_SCHED]: sch_cbq: fix watchdog scheduled too late

q->now is increased during dequeue and doesn't contain the current time
afterwards, resulting in a too large timeout value for the qdisc watchdog.
Use "now" instead, which still contains the current time.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched/sch_cbq.c

@@ -1070,7 +1070,7 @@ cbq_dequeue(struct Qdisc *sch)
 		sch->qstats.overlimits++;
 		if (q->wd_expires)
 			qdisc_watchdog_schedule(&q->watchdog,
-						q->now + q->wd_expires);
+						now + q->wd_expires);
 	}
 	return NULL;
 }