staging: r8188eu: replace custom hwaddr_aton_i() with mac_pton()

Replace custom hwaddr_aton_i() with mac_pton() in core/ioctl_linux.c
and remove the now unused functions hwaddr_aton_i() and hex2num_i().
Acked-by: Phillip Potter <phil@philpotter.co.uk>
Signed-off-by: Michael Straube <straube.linux@gmail.com>
Link: https://lore.kernel.org/r/20210812132057.22579-1-straube.linux@gmail.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/r8188eu/os_dep/ioctl_linux.c

@@ -89,44 +89,6 @@ static const char * const iw_operation_mode[] = {
 	"Secondary", "Monitor"
 };
 
-static int hex2num_i(char c)
-{
-	if (c >= '0' && c <= '9')
-		return c - '0';
-	if (c >= 'a' && c <= 'f')
-		return c - 'a' + 10;
-	if (c >= 'A' && c <= 'F')
-		return c - 'A' + 10;
-	return -1;
-}
-
-/**
- * hwaddr_aton - Convert ASCII string to MAC address
- * @txt: MAC address as a string (e.g., "00:11:22:33:44:55")
- * @addr: Buffer for the MAC address (ETH_ALEN = 6 bytes)
- * Returns: 0 on success, -1 on failure (e.g., string not a MAC address)
- */
-static int hwaddr_aton_i(const char *txt, u8 *addr)
-{
-	int i;
-
-	for (i = 0; i < 6; i++) {
-		int a, b;
-
-		a = hex2num_i(*txt++);
-		if (a < 0)
-			return -1;
-		b = hex2num_i(*txt++);
-		if (b < 0)
-			return -1;
-		*addr++ = (a << 4) | b;
-		if (i < 5 && *txt++ != ':')
-			return -1;
-	}
-
-	return 0;
-}
-
 void indicate_wx_scan_complete_event(struct adapter *padapter)
 {
 	union iwreq_data wrqu;
@@ -2512,7 +2474,7 @@ static int rtw_get_ap_info(struct net_device *dev,
 	while (phead != plist) {
 		pnetwork = container_of(plist, struct wlan_network, list);
 
-		if (hwaddr_aton_i(data, bssid)) {
+		if (!mac_pton(data, bssid)) {
 			DBG_88E("Invalid BSSID '%s'.\n", (u8 *)data);
 			spin_unlock_bh(&pmlmepriv->scanned_queue.lock);
 			return -EINVAL;