ath5k: 5211, don't crypt every protected frame

Set null key type even on ar5211, otherwise it en/decrypts every frame with
protected bit set which renders the card unusable on encrypted networks.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Cc: Luis R. Rodriguez <lrodriguez@atheros.com>
Cc: Bob Copeland <me@bobcopeland.com>
Acked-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath5k/pcu.c

@@ -1003,7 +1003,7 @@ int ath5k_hw_reset_key(struct ath5k_hw *ah, u16 entry)
 	 * Note2: Windows driver (ndiswrapper) sets this to
 	 *        0x00000714 instead of 0x00000007
 	 */
-	if (ah->ah_version > AR5K_AR5211) {
+	if (ah->ah_version >= AR5K_AR5211) {
 		ath5k_hw_reg_write(ah, AR5K_KEYTABLE_TYPE_NULL,
 				AR5K_KEYTABLE_TYPE(entry));