wireless: move mesh config length constant

This is a constant from the 802.11 specification.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c
index d3b6e1a6..82f568e 100644
--- a/net/mac80211/mesh.c
+++ b/net/mac80211/mesh.c
@@ -238,7 +238,7 @@
 
 	pos = skb_put(skb, 21);
 	*pos++ = WLAN_EID_MESH_CONFIG;
-	*pos++ = MESH_CFG_LEN;
+	*pos++ = IEEE80211_MESH_CONFIG_LEN;
 	/* Version */
 	*pos++ = 1;