mac80211: dont use interface indices in drivers

This patch gets rid of the if_id stuff where possible in favour of
a new per-virtual-interface structure "struct ieee80211_vif". This
structure is located at the end of the per-interface structure and
contains a variable length driver-use data area.

This has two advantages:
 * removes the need to look up interfaces by if_id, this is better
   for working with network namespaces and performance
 * allows drivers to store and retrieve per-interface data without
   having to allocate own lists/hash tables

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/adm8211.c b/drivers/net/wireless/adm8211.c
index 14d90a94..7979618 100644
--- a/drivers/net/wireless/adm8211.c
+++ b/drivers/net/wireless/adm8211.c
@@ -1312,7 +1312,8 @@
 	return 0;
 }
 
-static int adm8211_config_interface(struct ieee80211_hw *dev, int if_id,
+static int adm8211_config_interface(struct ieee80211_hw *dev,
+				    struct ieee80211_vif *vif,
 				    struct ieee80211_if_conf *conf)
 {
 	struct adm8211_priv *priv = dev->priv;