ath9k: Remove unused key xoring

This is not used anywhere in ath9k and is just making the code more
confusing.

Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath9k/main.c b/drivers/net/wireless/ath9k/main.c
index fd6cc73..28200ce 100644
--- a/drivers/net/wireless/ath9k/main.c
+++ b/drivers/net/wireless/ath9k/main.c
@@ -642,7 +642,7 @@
 	bool status;
 
 	status = ath9k_hw_set_keycache_entry(sc->sc_ah,
-		keyix, hk, mac, false);
+		keyix, hk, mac);
 
 	return status != false;
 }