batman-adv: use to_delayed_work

Use to_delayed_work() instead of open-coding it.

Signed-off-by: Geliang Tang <geliangtang@163.com>
Reviewed-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <a@unstable.cc>
diff --git a/net/batman-adv/network-coding.c b/net/batman-adv/network-coding.c
index b41719b..0d3bf43 100644
--- a/net/batman-adv/network-coding.c
+++ b/net/batman-adv/network-coding.c
@@ -714,7 +714,7 @@
 	struct batadv_priv *bat_priv;
 	unsigned long timeout;
 
-	delayed_work = container_of(work, struct delayed_work, work);
+	delayed_work = to_delayed_work(work);
 	priv_nc = container_of(delayed_work, struct batadv_priv_nc, work);
 	bat_priv = container_of(priv_nc, struct batadv_priv, nc);