misc: vmm: 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

vmm/src/api/dbus/mod.rs

@@ -10,6 +10,7 @@ use std::thread;
 use futures::channel::oneshot;
 use futures::{FutureExt, executor};
 use hypervisor::HypervisorType;
+use log::{error, warn};
 use seccompiler::{SeccompAction, apply_filter};
 use vmm_sys_util::eventfd::EventFd;
 use zbus::connection::Builder;