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/b43/xmit.c b/drivers/net/wireless/b43/xmit.c
index 419aca1..5014213 100644
--- a/drivers/net/wireless/b43/xmit.c
+++ b/drivers/net/wireless/b43/xmit.c
@@ -221,7 +221,7 @@
 	} else {
 		int fbrate_base100kbps = B43_RATE_TO_BASE100KBPS(rate_fb);
 		txhdr->dur_fb = ieee80211_generic_frame_duration(dev->wl->hw,
-								 dev->wl->if_id,
+								 txctl->vif,
 								 fragment_len,
 								 fbrate_base100kbps);
 	}
@@ -312,7 +312,7 @@
 		rts_rate_fb_ofdm = b43_is_ofdm_rate(rts_rate_fb);
 
 		if (txctl->flags & IEEE80211_TXCTL_USE_CTS_PROTECT) {
-			ieee80211_ctstoself_get(dev->wl->hw, dev->wl->if_id,
+			ieee80211_ctstoself_get(dev->wl->hw, txctl->vif,
 						fragment_data, fragment_len,
 						txctl,
 						(struct ieee80211_cts *)(txhdr->
@@ -320,7 +320,7 @@
 			mac_ctl |= B43_TX4_MAC_SENDCTS;
 			len = sizeof(struct ieee80211_cts);
 		} else {
-			ieee80211_rts_get(dev->wl->hw, dev->wl->if_id,
+			ieee80211_rts_get(dev->wl->hw, txctl->vif,
 					  fragment_data, fragment_len, txctl,
 					  (struct ieee80211_rts *)(txhdr->
 								   rts_frame));