[realtek] Print bad MAC address in debug message when inferring no EEPROM

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/drivers/net/realtek.c

 	 * hopefully have been programmed by the platform firmware.
 	 */
 	if ( ! is_valid_ether_addr ( netdev->hw_addr ) ) {
-		DBGC ( rtl, "REALTEK %p seems to have no EEPROM\n", rtl );
+		DBGC ( rtl, "REALTEK %p seems to have no EEPROM (MAC %s)\n",
+		       rtl, eth_ntoa ( netdev->hw_addr ) );
 		for ( i = 0 ; i < ETH_ALEN ; i++ )
 			netdev->hw_addr[i] = readb ( rtl->regs + RTL_IDR0 + i );
 	}