Remove some unnecessary "extern crate" statements

src/uu/sync/src/sync.rs

@@ -7,8 +7,6 @@
 
 /* Last synced with: sync (GNU coreutils) 8.13 */
 
-extern crate libc;
-
 use clap::{crate_version, Arg, ArgAction, Command};
 #[cfg(any(target_os = "linux", target_os = "android"))]
 use nix::errno::Errno;
@@ -34,7 +32,6 @@ static ARG_FILES: &str = "files";
 
 #[cfg(unix)]
 mod platform {
-    use super::libc;
     #[cfg(any(target_os = "linux", target_os = "android"))]
     use std::fs::File;
     #[cfg(any(target_os = "linux", target_os = "android"))]

src/uucore/src/lib/features/fsext.rs

@@ -11,7 +11,6 @@
 
 // spell-checker:ignore DATETIME subsecond (arch) bitrig ; (fs) cifs smbfs
 
-extern crate time;
 use time::macros::format_description;
 use time::UtcOffset;
 

src/uucore/src/lib/features/utmpx.rs

@@ -227,7 +227,6 @@ impl Utmpx {
         let (hostname, display) = host.split_once(':').unwrap_or((&host, ""));
 
         if !hostname.is_empty() {
-            extern crate dns_lookup;
             use dns_lookup::{getaddrinfo, AddrInfoHints};
 
             const AI_CANONNAME: i32 = 0x2;

src/uucore/src/lib/mods/backup_control.rs

@@ -200,8 +200,6 @@ impl Display for BackupError {
 pub mod arguments {
     use clap::ArgAction;
 
-    extern crate clap;
-
     pub static OPT_BACKUP: &str = "backupopt_backup";
     pub static OPT_BACKUP_NO_ARG: &str = "backupopt_b";
     pub static OPT_SUFFIX: &str = "backupopt_suffix";

src/uucore_procs/src/lib.rs

@@ -1,7 +1,6 @@
 // Copyright (C) ~ Roy Ivy III <rivy.dev@gmail.com>; MIT license
 // spell-checker:ignore backticks
 
-extern crate proc_macro;
 use std::{fs::File, io::Read, path::PathBuf};
 
 use proc_macro::{Literal, TokenStream, TokenTree};