sch_htb: fix doc warning in htb_deactivate()

Add description for parameters of htb_deactivate()
to fix gcc W=1 warnings:

net/sched/sch_htb.c:578: warning: Function parameter or member 'q' not described in 'htb_deactivate'
net/sched/sch_htb.c:578: warning: Function parameter or member 'cl' not described in 'htb_deactivate'
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched/sch_htb.c

@@ -594,6 +594,8 @@ static inline void htb_activate(struct htb_sched *q, struct htb_class *cl)
 
 /**
  * htb_deactivate - remove leaf cl from active feeds
+ * @q: the priority event queue
+ * @cl: the target class
  *
  * Make sure that leaf is active. In the other words it can't be called
  * with non-active leaf. It also removes class from the drop list.