firewire: cdev: use list_first_entry

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
diff --git a/drivers/firewire/fw-cdev.c b/drivers/firewire/fw-cdev.c
index 3c075b2..ead5c7b 100644
--- a/drivers/firewire/fw-cdev.c
+++ b/drivers/firewire/fw-cdev.c
@@ -180,7 +180,7 @@
 		return -ENODEV;
 
 	spin_lock_irqsave(&client->lock, flags);
-	event = container_of(client->event_list.next, struct event, link);
+	event = list_first_entry(&client->event_list, struct event, link);
 	list_del(&event->link);
 	spin_unlock_irqrestore(&client->lock, flags);