staging: rtl8723bs: hal: Remove set but unused variables

Removed four set but unused variables. Issue detected by gcc.
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Link: https://lore.kernel.org/r/20210430095319.23226-2-fmdefrancesco@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8723bs/hal/rtl8723b_hal_init.c

@@ -3897,14 +3897,11 @@ u8 GetHalDefVar8723B(struct adapter *padapter, enum hal_def_variable variable, v
 			u32 cmd;
 			u32 ra_info1, ra_info2;
 			u32 rate_mask1, rate_mask2;
-			u8 curr_tx_rate, curr_tx_sgi, hight_rate, lowest_rate;
 
 			cmd = 0x40000100 | mac_id;
 			rtw_write32(padapter, REG_HMEBOX_DBG_2_8723B, cmd);
 			msleep(10);
 			ra_info1 = rtw_read32(padapter, 0x2F0);
-			curr_tx_rate = ra_info1&0x7F;
-			curr_tx_sgi = (ra_info1>>7)&0x01;
 
 			cmd = 0x40000400 | mac_id;
 			rtw_write32(padapter, REG_HMEBOX_DBG_2_8723B, cmd);
@@ -3913,8 +3910,6 @@ u8 GetHalDefVar8723B(struct adapter *padapter, enum hal_def_variable variable, v
 			ra_info2 = rtw_read32(padapter, 0x2F4);
 			rate_mask1 = rtw_read32(padapter, 0x2F8);
 			rate_mask2 = rtw_read32(padapter, 0x2FC);
-			hight_rate = ra_info2&0xFF;
-			lowest_rate = (ra_info2>>8)  & 0xFF;
 
 		}
 		break;