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/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c
index ce574e9..33f273e 100644
--- a/net/batman-adv/distributed-arp-table.c
+++ b/net/batman-adv/distributed-arp-table.c
@@ -152,7 +152,7 @@
 	struct batadv_priv_dat *priv_dat;
 	struct batadv_priv *bat_priv;
 
-	delayed_work = container_of(work, struct delayed_work, work);
+	delayed_work = to_delayed_work(work);
 	priv_dat = container_of(delayed_work, struct batadv_priv_dat, work);
 	bat_priv = container_of(priv_dat, struct batadv_priv, dat);