staging: rtl8188eu: remove HW_VAR_TXPAUSE

The "HAL layer variable" HW_VAR_TXPAUSE is not used in this driver.
Remove its define and the code for setting and for reading a value.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20210725155902.32433-3-martin@kaiser.cx
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8188eu/hal/usb_halinit.c

@@ -1176,9 +1176,6 @@ void rtw_hal_set_hwreg(struct adapter *Adapter, u8 variable, u8 *val)
 			usb_write8(Adapter, REG_INIRTS_RATE_SEL, RateIndex);
 		}
 		break;
-	case HW_VAR_TXPAUSE:
-		usb_write8(Adapter, REG_TXPAUSE, *((u8 *)val));
-		break;
 	case HW_VAR_BCN_FUNC:
 		hw_var_set_bcn_func(Adapter, variable, val);
 		break;
@@ -1611,9 +1608,6 @@ void rtw_hal_get_hwreg(struct adapter *Adapter, u8 variable, u8 *val)
 	case HW_VAR_BASIC_RATE:
 		*((u16 *)(val)) = Adapter->HalData->BasicRateSet;
 		fallthrough;
-	case HW_VAR_TXPAUSE:
-		val[0] = usb_read8(Adapter, REG_TXPAUSE);
-		break;
 	case HW_VAR_BCN_VALID:
 		/* BCN_VALID, BIT16 of REG_TDECTRL = BIT0 of REG_TDECTRL+2 */
 		val[0] = (BIT(0) & usb_read8(Adapter, REG_TDECTRL + 2)) ? true : false;

drivers/staging/rtl8188eu/include/hal_intf.h

@@ -18,7 +18,6 @@ enum hw_variables {
 	HW_VAR_BSSID,
 	HW_VAR_INIT_RTS_RATE,
 	HW_VAR_BASIC_RATE,
-	HW_VAR_TXPAUSE,
 	HW_VAR_BCN_FUNC,
 	HW_VAR_CORRECT_TSF,
 	HW_VAR_CHECK_BSSID,