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>
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index 5a3bdaa..6ec2127 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -116,9 +116,9 @@
 		return ret;
 
 	if (ieee80211_vif_is_mesh(&sdata->vif) && params->mesh_id_len)
-		ieee80211_if_sta_set_mesh_id(&sdata->u.sta,
-					     params->mesh_id_len,
-					     params->mesh_id);
+		ieee80211_sdata_set_mesh_id(sdata,
+					    params->mesh_id_len,
+					    params->mesh_id);
 
 	if (sdata->vif.type != IEEE80211_IF_TYPE_MNTR || !flags)
 		return 0;