ath9k: Fix set_key error codes

Return -EOPNOTSUPP if the algorithm is not supported and -ENOSPC if
there is no room in the key cache. This avoids KERN_ERR printk in
mac80211 for "errors" that are actually expected to happen in normal
operating conditions.
Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath9k/main.c

@@ -817,7 +817,7 @@ static int ath_key_config(struct ath_softc *sc,
 		hk.kv_type = ATH9K_CIPHER_AES_CCM;
 		break;
 	default:
-		return -EINVAL;
+		return -EOPNOTSUPP;
 	}
 
 	hk.kv_len = key->keylen;
@@ -851,7 +851,7 @@ static int ath_key_config(struct ath_softc *sc,
 		else
 			idx = ath_reserve_key_cache_slot(sc);
 		if (idx < 0)
-			return -EIO; /* no free key cache entries */
+			return -ENOSPC; /* no free key cache entries */
 	}
 
 	if (key->alg == ALG_TKIP)