sctp: Use skb_queue_walk_safe() and skb_queue_split_tail_init().

/* A macro to walk a list of skbs.  */

#define sctp_skb_for_each(pos, head, tmp) \

for (pos = (head)->next;\

     tmp = (pos)->next, pos != ((struct sk_buff *)(head));\

     pos = tmp)

	skb_queue_walk_safe(head, pos, tmp)

/* A helper to append an entire skb list (list) to another (head). */

static inline void sctp_skb_list_tail(struct sk_buff_head *list,

	sctp_spin_lock_irqsave(&head->lock, flags);

	sctp_spin_lock(&list->lock);

	list_splice((struct list_head *)list, (struct list_head *)head->prev);

	head->qlen += list->qlen;

	list->qlen = 0;

	skb_queue_splice_tail_init(list, head);

	sctp_spin_unlock(&list->lock);

	sctp_spin_unlock_irqrestore(&head->lock, flags);