mac80211: reduce reliance on netdev

For bluetooth 3, we will most likely not have
a netdev for a virtual interface (sdata), so
prepare for that by reducing the reliance on
having a netdev. This patch moves the name
and address fields into the sdata struct and
uses them from there all over. Some work is
needed to keep them sync'ed, but that's not
a lot of work and in slow paths anyway.

In doing so, this also reduces the number of
pointer dereferences in many places, because
of things like sdata->dev->dev_addr becoming
sdata->vif.addr.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

net/mac80211/cfg.c

@@ -729,7 +729,7 @@ static int ieee80211_add_station(struct wiphy *wiphy, struct net_device *dev,
 	} else
 		sdata = IEEE80211_DEV_TO_SUB_IF(dev);
 
-	if (compare_ether_addr(mac, dev->dev_addr) == 0)
+	if (compare_ether_addr(mac, sdata->vif.addr) == 0)
 		return -EINVAL;
 
 	if (is_multicast_ether_addr(mac))