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/vsock/csm/connection.rs

@@ -85,6 +85,8 @@ use std::num::Wrapping;
 use std::os::unix::io::{AsRawFd, RawFd};
 use std::time::{Duration, Instant};
 
+use log::{debug, error, info, warn};
+
 use super::super::defs::uapi;
 use super::super::packet::VsockPacket;
 use super::super::{Result as VsockResult, VsockChannel, VsockEpollListener, VsockError};