misc: rate_limiter: 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

rate_limiter/src/group.rs

@@ -10,6 +10,7 @@ use std::os::unix::io::{AsRawFd, FromRawFd, RawFd};
 use std::sync::{Arc, Mutex};
 use std::{io, result, thread};
 
+use log::{error, info, warn};
 use thiserror::Error;
 use vmm_sys_util::eventfd::EventFd;
 

rate_limiter/src/lib.rs

@@ -43,8 +43,6 @@
 //! It is meant to be used in an external event loop and thus implements the `AsRawFd`
 //! trait and provides an *event-handler* as part of its API. This *event-handler*
 //! needs to be called by the user on every event on the rate limiter's `AsRawFd` FD.
-#[macro_use]
-extern crate log;
 
 use std::io;
 use std::os::unix::io::{AsRawFd, RawFd};
@@ -52,6 +50,7 @@ use std::sync::Mutex;
 use std::sync::atomic::{AtomicBool, Ordering};
 use std::time::{Duration, Instant};
 
+use log::error;
 use thiserror::Error;
 use vmm_sys_util::timerfd::TimerFd;