net: sched: use skb_list_walk_safe helper for gso segments

This is a straight-forward conversion case for the new function, keeping
the flow of the existing code as intact as possible.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched/sch_cake.c

@@ -1682,8 +1682,7 @@ static s32 cake_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 		if (IS_ERR_OR_NULL(segs))
 			return qdisc_drop(skb, sch, to_free);
 
-		while (segs) {
-			nskb = segs->next;
+		skb_list_walk_safe(segs, segs, nskb) {
 			skb_mark_not_on_list(segs);
 			qdisc_skb_cb(segs)->pkt_len = segs->len;
 			cobalt_set_enqueue_time(segs, now);
@@ -1696,7 +1695,6 @@ static s32 cake_enqueue(struct sk_buff *skb, struct Qdisc *sch,
 			slen += segs->len;
 			q->buffer_used += segs->truesize;
 			b->packets++;
-			segs = nskb;
 		}
 
 		/* stats */

net/sched/sch_tbf.c

@@ -155,8 +155,7 @@ static int tbf_segment(struct sk_buff *skb, struct Qdisc *sch,
 		return qdisc_drop(skb, sch, to_free);
 
 	nb = 0;
-	while (segs) {
-		nskb = segs->next;
+	skb_list_walk_safe(segs, segs, nskb) {
 		skb_mark_not_on_list(segs);
 		qdisc_skb_cb(segs)->pkt_len = segs->len;
 		len += segs->len;
@@ -167,7 +166,6 @@ static int tbf_segment(struct sk_buff *skb, struct Qdisc *sch,
 		} else {
 			nb++;
 		}
-		segs = nskb;
 	}
 	sch->q.qlen += nb;
 	if (nb > 1)