rust: Stop using extern crate and #[macro_use]

Rust 2018 makes this much nicer now.

Closes: #1812
Approved by: lucab

rust/src/journal.rs

@@ -16,11 +16,9 @@
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
-extern crate systemd;
-
-use self::systemd::id128::Id128;
-use self::systemd::journal;
 use failure::Fallible;
+use systemd::id128::Id128;
+use systemd::journal;
 
 static OSTREE_FINALIZE_STAGED_SERVICE: &'static str = "ostree-finalize-staged.service";
 static OSTREE_DEPLOYMENT_FINALIZING_MSG_ID: &'static str = "e8646cd63dff4625b77909a8e7a40994";

rust/src/lib.rs

@@ -16,28 +16,6 @@
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
-extern crate c_utf8;
-extern crate clap;
-extern crate curl;
-#[macro_use]
-extern crate failure;
-extern crate gio_sys;
-extern crate glib;
-extern crate glib_sys;
-extern crate indicatif;
-extern crate libc;
-extern crate openat;
-extern crate rayon;
-extern crate tempfile;
-
-#[macro_use]
-extern crate lazy_static;
-#[macro_use]
-extern crate serde_derive;
-extern crate serde;
-extern crate serde_json;
-extern crate serde_yaml;
-
 // pub(crate) utilities
 mod ffiutil;
 mod openat_utils;

rust/src/progress.rs

@@ -16,9 +16,8 @@
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
-extern crate indicatif;
-
 use indicatif::{ProgressBar, ProgressDrawTarget, ProgressStyle};
+use lazy_static::lazy_static;
 use std::borrow::Cow;
 use std::sync::Mutex;
 

rust/src/treefile.rs

@@ -24,6 +24,7 @@ use c_utf8::CUtf8Buf;
 use failure::Fallible;
 use failure::ResultExt;
 use openat;
+use serde_derive::{Deserialize, Serialize};
 use serde_json;
 use serde_yaml;
 use std::collections::HashMap;

rust/src/utils.rs

@@ -16,7 +16,7 @@
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
-use failure::Fallible;
+use failure::{bail, Fallible};
 use std::collections::HashMap;
 use std::io::prelude::*;
 use std::{fs, io};