wl1251: don't build null data template in wl1251_op_config()

The bssid can be zero when null data template is set in wl1251_op_config().
It's enough, and especially safe, to set it once after association.
Signed-off-by: Kalle Valo <kalle.valo@nokia.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/wl12xx/wl1251_main.c

@@ -629,10 +629,6 @@ static int wl1251_op_config(struct ieee80211_hw *hw, u32 changed)
 			goto out_sleep;
 	}
 
-	ret = wl1251_build_null_data(wl);
-	if (ret < 0)
-		goto out_sleep;
-
 	if (conf->flags & IEEE80211_CONF_PS && !wl->psm_requested) {
 		wl1251_debug(DEBUG_PSM, "psm enabled");