mac80211: set mesh formation field properly

Cap max peerings at 63 in accordance with IEEE-2012 8.4.2.100.7.
Triggers a beacon regeneration every time the number of peerings changes.
Previously this would only happen if the "accepting peerings" bit changed.

Signed-off-by: Jacob Minshall <jacob@cozybit.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/mesh.h b/net/mac80211/mesh.h
index da15877..8b4d9a3 100644
--- a/net/mac80211/mesh.h
+++ b/net/mac80211/mesh.h
@@ -324,14 +324,14 @@
 u32 mesh_plink_inc_estab_count(struct ieee80211_sub_if_data *sdata)
 {
 	atomic_inc(&sdata->u.mesh.estab_plinks);
-	return mesh_accept_plinks_update(sdata);
+	return mesh_accept_plinks_update(sdata) | BSS_CHANGED_BEACON;
 }
 
 static inline
 u32 mesh_plink_dec_estab_count(struct ieee80211_sub_if_data *sdata)
 {
 	atomic_dec(&sdata->u.mesh.estab_plinks);
-	return mesh_accept_plinks_update(sdata);
+	return mesh_accept_plinks_update(sdata) | BSS_CHANGED_BEACON;
 }
 
 static inline int mesh_plink_free_count(struct ieee80211_sub_if_data *sdata)