staging: r8188eu: simplify update_sta_support_rate params

The update_sta_support_rate function takes a pointer to information
elements and the total length of all these elements. Use our variables
for pointer and length instead of calculating them manually.

Tested-by: Philipp Hortmann <philipp.g.hortmann@gmail.com> # Edimax N150
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20221126160129.178697-7-martin@kaiser.cxSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/r8188eu/core/rtw_mlme_ext.c

@@ -621,7 +621,7 @@ static void OnBeacon(struct adapter *padapter, struct recv_frame *precv_frame)
 					return;
 
 				/* get supported rate */
-				if (update_sta_support_rate(padapter, (pframe + WLAN_HDR_A3_LEN + _BEACON_IE_OFFSET_), (len - WLAN_HDR_A3_LEN - _BEACON_IE_OFFSET_), cam_idx) == _FAIL) {
+				if (update_sta_support_rate(padapter, ie_ptr, ie_len, cam_idx) == _FAIL) {
 					pmlmeinfo->FW_sta_info[cam_idx].status = 0;
 					return;
 				}