mac80211: constify ieee80211_if_conf.bssid

Then one place can be a static const.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index c78304d..6f0fe35 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -176,7 +176,7 @@
 	else if (sdata->vif.type == NL80211_IFTYPE_AP)
 		conf.bssid = sdata->dev->dev_addr;
 	else if (ieee80211_vif_is_mesh(&sdata->vif)) {
-		u8 zero[ETH_ALEN] = { 0 };
+		static const u8 zero[ETH_ALEN] = { 0 };
 		conf.bssid = zero;
 	} else {
 		WARN_ON(1);