sudo: Simplify a bit

src/bin/sudo.rs

@@ -31,11 +31,6 @@ AUTHOR
 "#; /* @MANEND */
 
 pub fn main() {
-    let stdin = io::stdin();
-    let mut stdin = stdin.lock();
-    let stdout = io::stdout();
-    let mut stdout = stdout.lock();
-
     let mut args = env::args().skip(1);
     let cmd = args.next().unwrap_or_else(|| {
         eprintln!("sudo: no command provided");
@@ -73,12 +68,11 @@ pub fn main() {
 
     loop {
         print!("[sudo] password for {}: ", user.user);
-        let _ = stdout.flush();
+        let _ = io::stdout().flush();
 
-        match stdin.read_passwd(&mut stdout).unwrap() {
+        match io::stdin().read_passwd(&mut io::stdout()).unwrap() {
             Some(password) => {
-                write!(stdout, "\n").unwrap();
-                let _ = stdout.flush();
+                println!();
 
                 if user.verify_passwd(&password) {
                     break;
@@ -91,7 +85,7 @@ pub fn main() {
                 }
             }
             None => {
-                write!(stdout, "\n").unwrap();
+                println!();
                 exit(1);
             }
         }