add license headers

src/uu/lscpu/src/lscpu.rs

@@ -1,3 +1,8 @@
+// This file is part of the uutils util-linux package.
+//
+// For the full copyright and license information, please view the LICENSE
+// file that was distributed with this source code.
+
 use regex::Regex;
 use std::fs;
 use sysinfo::System;

src/uu/pwdx/src/pwdx.rs

@@ -1,3 +1,8 @@
+// This file is part of the uutils util-linux package.
+//
+// For the full copyright and license information, please view the LICENSE
+// file that was distributed with this source code.
+
 use std::env;
 use std::fs;
 use std::path::Path;

src/uu/renice/src/renice.rs

@@ -1,3 +1,8 @@
+// This file is part of the uutils util-linux package.
+//
+// For the full copyright and license information, please view the LICENSE
+// file that was distributed with this source code.
+
 use libc::{c_char, c_int, execvp, PRIO_PROCESS};
 use std::env;
 use std::io::{Error, Write};