refactor(udp): add use declaration for tracing debug and error

quinn-udp/src/unix.rs

@@ -13,6 +13,7 @@ use std::{
 };
 
 use socket2::SockRef;
+use tracing::{debug, error};
 
 use super::{
  cmsg, log_sendmsg_error, EcnCodepoint, RecvMeta, Transmit, UdpSockRef, IO_ERROR_LOG_INTERVAL,
@@ -87,7 +88,7 @@ impl UdpSocketState {
  if is_ipv4 || !io.only_v6()? {
  if let Err(err) = set_socket_option(&*io, libc::IPPROTO_IP, libc::IP_RECVTOS, OPTION_ON)
  {
- tracing::debug!("Ignoring error setting IP_RECVTOS on socket: {err:?}",);
+ debug!("Ignoring error setting IP_RECVTOS on socket: {err:?}",);
  }
  }
 
@@ -283,7 +284,7 @@ fn send(
  // Prevent new transmits from being scheduled using GSO. Existing GSO transmits
  // may already be in the pipeline, so we need to tolerate additional failures.
  if state.max_gso_segments() > 1 {
- tracing::error!("got transmit error, halting segmentation offload");
+ error!("got transmit error, halting segmentation offload");
  state
  .max_gso_segments
  .store(1, std::sync::atomic::Ordering::Relaxed);