staging: r8188eu: remove unused variable from UpdateHalRAMask8188EUsb

Remove the 'arg' variable from the block inside the if statement in the
UpdateHalRAMask8188EUsb function in hal/usb_halinit.c, as due to the
recent DBG_88E cleanup series, this is now set but not used. Also remove
the rest of the lines in this block that further modify 'arg' as they
are superfluous, due to it never being used afterwards.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Phillip Potter <phil@philpotter.co.uk>
Link: https://lore.kernel.org/r/20220222233506.72778-1-phil@philpotter.co.ukSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/r8188eu/hal/usb_halinit.c

@@ -1528,12 +1528,6 @@ void UpdateHalRAMask8188EUsb(struct adapter *adapt, u32 mac_id, u8 rssi_level)
 	init_rate = get_highest_rate_idx(mask) & 0x3f;
 
 	if (haldata->fw_ractrl) {
-		u8 arg;
-
-		arg = mac_id & 0x1f;/* MACID */
-		arg |= BIT(7);
-		if (shortGIrate)
-			arg |= BIT(5);
 		mask |= ((raid << 28) & 0xf0000000);
 		psta->ra_mask = mask;
 		mask |= ((raid << 28) & 0xf0000000);