staging: vt6656: Remove logically dead code

In the start of the "vnt_rf_set_txpower" function the "power" variable
is set at most to VNT_RF_MAX_POWER (hex = 0x3f, dec = 63). Then, in the
switch statement there are four comparisons with the "power" variable
against AL7230_PWR_IDX_LEN (dec = 64), VT3226_PWR_IDX_LEN (dec = 64),
VT3342_PWR_IDX_LEN (dec = 64). Due to all the commented comparisons are
to check if the "power" variable is "greater than or equal" to 64, this
never happens. So, remove the logically dead code.

Also, remove all the defines that are no longer required.

Addresses-Coverity-ID: 1230228 ("Logically dead code")
Fixes: f53d9f12 ("staging: vt6656: rf.c additional power.")
Signed-off-by: Oscar Carter <oscar.carter@gmx.com>
Link: https://lore.kernel.org/r/20200510090950.7633-1-oscar.carter@gmx.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/vt6656/rf.c

@@ -28,15 +28,9 @@
 #include "usbpipe.h"
 
 #define CB_AL2230_INIT_SEQ    15
-
 #define CB_AL7230_INIT_SEQ    16
-#define AL7230_PWR_IDX_LEN    64
-
 #define CB_VT3226_INIT_SEQ    11
-#define VT3226_PWR_IDX_LEN    64
-
 #define CB_VT3342_INIT_SEQ    13
-#define VT3342_PWR_IDX_LEN    64
 
 static u8 al2230_init_table[CB_AL2230_INIT_SEQ][3] = {
 	{0x03, 0xf7, 0x90},
@@ -658,9 +652,6 @@ static int vnt_rf_set_txpower(struct vnt_private *priv, u8 power,
 		if (ret)
 			return ret;
 
-		if (power >= AL7230_PWR_IDX_LEN)
-			return -EINVAL;
-
 		/*
 		 * 0x080F1B00 for 3 wire control TxGain(D10)
 		 * and 0x31 as TX Gain value
@@ -671,16 +662,11 @@ static int vnt_rf_set_txpower(struct vnt_private *priv, u8 power,
 		break;
 
 	case RF_VT3226:
-		if (power >= VT3226_PWR_IDX_LEN)
-			return -EINVAL;
 		power_setting = ((0x3f - power) << 20) | (0x17 << 8);
 
 		ret = vnt_rf_write_embedded(priv, power_setting);
 		break;
 	case RF_VT3226D0:
-		if (power >= VT3226_PWR_IDX_LEN)
-			return -EINVAL;
-
 		if (ch->flags & IEEE80211_CHAN_NO_OFDM) {
 			u16 hw_value = ch->hw_value;
 
@@ -731,9 +717,6 @@ static int vnt_rf_set_txpower(struct vnt_private *priv, u8 power,
 		break;
 
 	case RF_VT3342A0:
-		if (power >= VT3342_PWR_IDX_LEN)
-			return -EINVAL;
-
 		power_setting =  ((0x3f - power) << 20) | (0x27 << 8);
 
 		ret = vnt_rf_write_embedded(priv, power_setting);