message: Fix examples/arp_packet.rs
  Instead of returning the next received arp packet, wait for receiving arp packet from the target.
diff: @@ -58,13 +58,16 @@ fn get_mac_through_arp(interface: NetworkInterface, target_ip: Ipv4Addr) -> MacA
  println!("Sent ARP request");
  - let buf = receiver.next().unwrap();
  -
  + while let buf = receiver.next().unwrap() {
  let arp = ArpPacket::new(&buf[MutableEthernetPacket::minimum_packet_size()..]).unwrap();
  -
  + if arp.get_sender_proto_addr() == target_ip
  + && arp.get_target_hw_addr() == interface.mac.unwrap()
  + {
  println!("Received reply");
  -
  - arp.get_sender_hw_addr()
  + return arp.get_sender_hw_addr();
  + }
  + }
  + panic!("Never reach here")
  }
  fn main() {
  