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/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index 7c8409e..56dee37 100644
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -370,7 +370,7 @@
 #define IEEE80211_MS_TO_TU(x)           (((x) * 1000) / 1024)
 
 struct ath_beacon_config {
-	u16 beacon_interval;
+	int beacon_interval;
 	u16 listen_interval;
 	u16 dtim_period;
 	u16 bmiss_timeout;
@@ -633,8 +633,6 @@
 	struct ath9k_hw_cal_data caldata;
 	int last_rssi;
 
-	int beacon_interval;
-
 #ifdef CONFIG_ATH9K_DEBUGFS
 	struct ath9k_debug debug;
 	spinlock_t nodes_lock;