net_sched: sfq: remove unused macro

not used anymore since ddecf0f4
(net_sched: sfq: add optional RED on top of SFQ).
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Acked-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/sched/sch_sfq.c

@@ -310,11 +310,6 @@ static inline void slot_queue_add(struct sfq_slot *slot, struct sk_buff *skb)
 	slot->skblist_prev = skb;
 }
 
-#define	slot_queue_walk(slot, skb)		\
-	for (skb = slot->skblist_next;		\
-	     skb != (struct sk_buff *)slot;	\
-	     skb = skb->next)
-
 static unsigned int sfq_drop(struct Qdisc *sch)
 {
 	struct sfq_sched_data *q = qdisc_priv(sch);