misc: virtio-devices: 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

virtio-devices/src/epoll_helper.rs

@@ -14,6 +14,7 @@ use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::{Arc, Barrier};
 use std::thread;
 
+use log::info;
 use thiserror::Error;
 use vmm_sys_util::eventfd::EventFd;