misc: vhost_user_net: drop extern crate, use modern rust

This commit is part of a series of similar commits.

Signed-off-by: Philipp Schuster <philipp.schuster@cyberus-technology.de>
On-behalf-of: SAP philipp.schuster@sap.com

vhost_user_net/src/lib.rs

@@ -13,7 +13,7 @@ use std::sync::{Arc, Mutex, RwLock};
 use std::{io, process};
 
 use libc::EFD_NONBLOCK;
-use log::*;
+use log::error;
 use net_util::{
     MacAddr, NetCounters, NetQueuePair, OpenTapError, RxVirtio, Tap, TxVirtio, open_tap,
 };