mac80211: split off mesh handling entirely

This patch splits off mesh handling from the STA/IBSS.
Unfortunately it increases mesh code size a bit, but I
think it makes things clearer. The patch also reduces
per-interface run-time memory usage.

Also clean up a few places where ifdef is not required.

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

net/mac80211/scan.c

@@ -476,6 +476,7 @@ void ieee80211_scan_completed(struct ieee80211_hw *hw)
 
  done:
 	ieee80211_mlme_notify_scan_completed(local);
+	ieee80211_mesh_notify_scan_completed(local);
 }
 EXPORT_SYMBOL(ieee80211_scan_completed);