message: remove memory leak
  free packet buffer if the packet is dropped
diff: @@ -215,11 +215,13 @@ static void uhyve_netif_poll(void)
  #endif
  - //forward packet to LwIP
  - if (tcpip_callback_with_block(consume_packet, p, 0) == ERR_OK)
  + //forward packet to the IP thread
  + if (tcpip_callback_with_block(consume_packet, p, 0) == ERR_OK) {
  LINK_STATS_INC(link.recv);
  - else
  + } else {
  LINK_STATS_INC(link.drop);
  + pbuf_free(p);
  + }
  } else {
  LOG_ERROR("uhyve_netif_poll: not enough memory!\n");
  LINK_STATS_INC(link.memerr);
  