batman-adv: rename global if_list to hardif_list

Batman-adv works with "hard interfaces" as well as "soft interfaces".
The new name should better make clear which kind of interfaces this
list stores.

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
diff --git a/net/batman-adv/main.h b/net/batman-adv/main.h
index 06b5b99..dc24869 100644
--- a/net/batman-adv/main.h
+++ b/net/batman-adv/main.h
@@ -122,7 +122,7 @@
 #define REVISION_VERSION_STR " "REVISION_VERSION
 #endif
 
-extern struct list_head if_list;
+extern struct list_head hardif_list;
 
 extern unsigned char broadcast_addr[];
 extern struct workqueue_struct *bat_event_workqueue;