mac80211: improve cleanup when leaving mesh

It is not necessary to stop the mesh beacon in the mac80211 ndo_stop
handler, since cfg80211 has already left the mesh on NETDEV_GOING_DOWN
notification.

Also some improvements to ieee80211_stop_mesh():

 - flush mpath entries.
 - flush sta entries per-sdata so we don't remove entries belonging to
   other vifs on the same hw.

Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c
index 571d518..035cd0c 100644
--- a/net/mac80211/mesh.c
+++ b/net/mac80211/mesh.c
@@ -621,9 +621,13 @@
 
 	netif_carrier_off(sdata->dev);
 
+	/* stop the beacon */
 	ifmsh->mesh_id_len = 0;
 	ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON_ENABLED);
-	sta_info_flush(local, NULL);
+
+	/* flush STAs and mpaths on this iface */
+	sta_info_flush(sdata->local, sdata);
+	mesh_path_flush_by_iface(sdata);
 
 	del_timer_sync(&sdata->u.mesh.housekeeping_timer);
 	del_timer_sync(&sdata->u.mesh.mesh_path_root_timer);