ath9k: Remove redundant beacon_interval

The variable appears in both ath_softc and ath_beacon_config.
The struct ath_beacon_config is embedded in ath_softc. The redundant
variable was added by commit id 57c4d7b4c4986037be51476b8e3025d5ba18d8b8.

Signed-off-by: Steve Brown <sbrown@cortland.com>
Reviewed-by: Mohammed Shafi <shafi.ath9k@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/beacon.c b/drivers/net/wireless/ath/ath9k/beacon.c
index fcb36ab..ed6e7d6 100644
--- a/drivers/net/wireless/ath/ath9k/beacon.c
+++ b/drivers/net/wireless/ath/ath9k/beacon.c
@@ -226,6 +226,7 @@
 	struct ath_vif *avp;
 	struct ath_buf *bf;
 	struct sk_buff *skb;
+	struct ath_beacon_config *cur_conf = &sc->cur_beacon_conf;
 	__le64 tstamp;
 
 	avp = (void *)vif->drv_priv;
@@ -282,7 +283,7 @@
 		u64 tsfadjust;
 		int intval;
 
-		intval = sc->beacon_interval ? : ATH_DEFAULT_BINTVAL;
+		intval = cur_conf->beacon_interval ? : ATH_DEFAULT_BINTVAL;
 
 		/*
 		 * Calculate the TSF offset for this beacon slot, i.e., the
@@ -346,6 +347,7 @@
 void ath_beacon_tasklet(unsigned long data)
 {
 	struct ath_softc *sc = (struct ath_softc *)data;
+	struct ath_beacon_config *cur_conf = &sc->cur_beacon_conf;
 	struct ath_hw *ah = sc->sc_ah;
 	struct ath_common *common = ath9k_hw_common(ah);
 	struct ath_buf *bf = NULL;
@@ -393,7 +395,7 @@
 	 * on the tsf to safeguard against missing an swba.
 	 */
 
-	intval = sc->beacon_interval ? : ATH_DEFAULT_BINTVAL;
+	intval = cur_conf->beacon_interval ? : ATH_DEFAULT_BINTVAL;
 
 	tsf = ath9k_hw_gettsf64(ah);
 	tsftu = TSF_TO_TU(tsf>>32, tsf);