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/hw.h b/drivers/net/wireless/ath9k/hw.h
index 5ec416b..89936a0 100644
--- a/drivers/net/wireless/ath9k/hw.h
+++ b/drivers/net/wireless/ath9k/hw.h
@@ -584,7 +584,7 @@
 bool ath9k_hw_keysetmac(struct ath_hw *ah, u16 entry, const u8 *mac);
 bool ath9k_hw_set_keycache_entry(struct ath_hw *ah, u16 entry,
 				 const struct ath9k_keyval *k,
-				 const u8 *mac, int xorKey);
+				 const u8 *mac);
 bool ath9k_hw_keyisvalid(struct ath_hw *ah, u16 entry);
 
 /* GPIO / RFKILL / Antennae */