net: atm: use seq_list_foo() helpers

Simplify seq_file code.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/atm/proc.c

@@ -238,7 +238,7 @@ static int atm_dev_seq_show(struct seq_file *seq, void *v)
 		"Itf Type    ESI/\"MAC\"addr "
 		"AAL(TX,err,RX,err,drop) ...               [refcnt]\n";
 
-	if (v == SEQ_START_TOKEN)
+	if (v == &atm_devs)
 		seq_puts(seq, atm_dev_banner);
 	else {
 		struct atm_dev *dev = list_entry(v, struct atm_dev, dev_list);

net/atm/resources.c

@@ -444,21 +444,10 @@ int atm_dev_ioctl(unsigned int cmd, void __user *arg, int compat)
 	return error;
 }
 
-static inline void *dev_get_idx(loff_t left)
-{
-	struct list_head *p;
-
-	list_for_each(p, &atm_devs) {
-		if (!--left)
-			break;
-	}
-	return (p != &atm_devs) ? p : NULL;
-}
-
 void *atm_dev_seq_start(struct seq_file *seq, loff_t *pos)
 {
 	mutex_lock(&atm_dev_mutex);
-	return *pos ? dev_get_idx(*pos) : SEQ_START_TOKEN;
+	return seq_list_start_head(&atm_devs, *pos);
 }
 
 void atm_dev_seq_stop(struct seq_file *seq, void *v)
@@ -468,8 +457,5 @@ void atm_dev_seq_stop(struct seq_file *seq, void *v)
 
 void *atm_dev_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 {
-	++*pos;
-	v = (v == SEQ_START_TOKEN)
-		? atm_devs.next : ((struct list_head *)v)->next;
-	return (v == &atm_devs) ? NULL : v;
+	return seq_list_next(v, &atm_devs, pos);
 }