ethernet: fix interface discovery on c33

Author: pennam

libraries/Ethernet/src/Ethernet.cpp

@@ -54,9 +54,9 @@ EthernetLinkStatus EthernetClass::linkStatus() {
 EthernetHardwareStatus EthernetClass::hardwareStatus() {
 	const struct device *const dev = DEVICE_DT_GET(DT_COMPAT_GET_ANY_STATUS_OKAY(ethernet_phy));
 	if (device_is_ready(dev)) {
-		for (int i = 1; i < 3; i++) {
+		for (int i = 1; i < 4; i++) {
 			auto _if = net_if_get_by_index(i);
-			if (!net_eth_type_is_wifi(_if)) {
+			if (_if && !net_eth_type_is_wifi(_if)) {
 				netif = _if;
 				break;
 			}