xfrm: remove the xfrm_queue_purge definition

The task of xfrm_queue_purge is same as skb_queue_purge, so remove it
Signed-off-by: NLi RongQing <roy.qing.li@gmail.com>
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

net/xfrm/xfrm_policy.c

@@ -315,14 +315,6 @@ void xfrm_policy_destroy(struct xfrm_policy *policy)
 }
 EXPORT_SYMBOL(xfrm_policy_destroy);
 
-static void xfrm_queue_purge(struct sk_buff_head *list)
-{
-	struct sk_buff *skb;
-
-	while ((skb = skb_dequeue(list)) != NULL)
-		kfree_skb(skb);
-}
-
 /* Rule must be locked. Release descentant resources, announce
  * entry dead. The rule must be unlinked from lists to the moment.
  */
@@ -335,7 +327,7 @@ static void xfrm_policy_kill(struct xfrm_policy *policy)
 
 	if (del_timer(&policy->polq.hold_timer))
 		xfrm_pol_put(policy);
-	xfrm_queue_purge(&policy->polq.hold_queue);
+	skb_queue_purge(&policy->polq.hold_queue);
 
 	if (del_timer(&policy->timer))
 		xfrm_pol_put(policy);
@@ -1955,7 +1947,7 @@ static void xfrm_policy_queue_process(unsigned long arg)
 
 purge_queue:
 	pq->timeout = 0;
-	xfrm_queue_purge(&pq->hold_queue);
+	skb_queue_purge(&pq->hold_queue);
 	xfrm_pol_put(pol);
 }