ath9k: fix keycache leak in split tkip case

If split tkip key is used, ath_delete_key should delete
rx key and rx mic key. This patch fixes the leak of hw
keycache in the case.
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/main.c

@@ -809,6 +809,7 @@ static void ath_key_delete(struct ath_common *common, struct ieee80211_key_conf
 
 	clear_bit(key->hw_key_idx + 64, common->keymap);
 	if (common->splitmic) {
+		ath9k_hw_keyreset(ah, key->hw_key_idx + 32);
 		clear_bit(key->hw_key_idx + 32, common->keymap);
 		clear_bit(key->hw_key_idx + 64 + 32, common->keymap);
 	}