ath9k: make ath9k_setpower function as static

Signed-off-by: Mohammed Shafi Shajakhan <mshajakhan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index 05a9094..097225d 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -67,7 +67,7 @@
 	return pending;
 }
 
-bool ath9k_setpower(struct ath_softc *sc, enum ath9k_power_mode mode)
+static bool ath9k_setpower(struct ath_softc *sc, enum ath9k_power_mode mode)
 {
 	unsigned long flags;
 	bool ret;