staging: vt6656: correct packet types for CTS protect, mode.

It appears that the driver still transmits in CTS protect mode even
though it is not enabled in mac80211.

That is both packet types PK_TYPE_11GA and PK_TYPE_11GB both use CTS protect.
The only difference between them GA does not use B rates.

Find if only B rate in GB or GA in protect mode otherwise transmit packets
as PK_TYPE_11A.

Cc: stable <stable@vger.kernel.org>
Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Link: https://lore.kernel.org/r/9c1323ff-dbb3-0eaa-43e1-9453f7390dc0@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/vt6656/device.h

@@ -52,6 +52,8 @@
 #define RATE_AUTO	12
 
 #define MAX_RATE			12
+#define VNT_B_RATES	(BIT(RATE_1M) | BIT(RATE_2M) |\
+			BIT(RATE_5M) | BIT(RATE_11M))
 
 /*
  * device specific

drivers/staging/vt6656/rxtx.c

@@ -815,10 +815,14 @@ int vnt_tx_packet(struct vnt_private *priv, struct sk_buff *skb)
 		if (info->band == NL80211_BAND_5GHZ) {
 			pkt_type = PK_TYPE_11A;
 		} else {
-			if (tx_rate->flags & IEEE80211_TX_RC_USE_CTS_PROTECT)
+			if (tx_rate->flags & IEEE80211_TX_RC_USE_CTS_PROTECT) {
+				if (priv->basic_rates & VNT_B_RATES)
 					pkt_type = PK_TYPE_11GB;
 				else
 					pkt_type = PK_TYPE_11GA;
+			} else {
+				pkt_type = PK_TYPE_11A;
+			}
 		}
 	} else {
 		pkt_type = PK_TYPE_11B;