mac80211: implement the meshconf formation info field

The Mesh Configuration Formation Info field contains the number of
neighbors.  This means that the beacon must be updated every time a
peer joins or leaves.

Signed-off-by: Rui Paulo <rpaulo@gmail.com>
Signed-off-by: Javier Cardona <rpaulo@gmail.com>
Reviewed-by: Andrey Yurovsky <andrey@cozybit.com>
Tested-by: Brian Cavagnolo <brian@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/mesh_plink.c b/net/mac80211/mesh_plink.c
index ffcbad7..f98c8d2 100644
--- a/net/mac80211/mesh_plink.c
+++ b/net/mac80211/mesh_plink.c
@@ -65,6 +65,7 @@
 {
 	atomic_inc(&sdata->u.mesh.mshstats.estab_plinks);
 	mesh_accept_plinks_update(sdata);
+	ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
 }
 
 static inline
@@ -72,6 +73,7 @@
 {
 	atomic_dec(&sdata->u.mesh.mshstats.estab_plinks);
 	mesh_accept_plinks_update(sdata);
+	ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_BEACON);
 }
 
 /**