Add cfg gate to libc import to satisfy clippy on windows

Author: iburaky2

src/uu/touch/src/touch.rs

@@ -23,6 +23,7 @@ use std::io::{Error, ErrorKind};
 use std::path::{Path, PathBuf};
 use uucore::display::Quotable;
 use uucore::error::{FromIo, UResult, USimpleError};
+#[cfg(unix)]
 use uucore::libc;
 use uucore::parser::shortcut_value_parser::ShortcutValueParser;
 use uucore::translate;