fix clippy warnings

tests/by-util/test_basename.rs

@@ -1,4 +1,5 @@
 use crate::common::util::*;
+#[cfg(any(unix, target_os = "redox"))]
 use std::ffi::OsStr;
 
 #[test]
@@ -123,6 +124,7 @@ fn test_too_many_args_output() {
     );
 }
 
+#[cfg(any(unix, target_os = "redox"))]
 fn test_invalid_utf8_args(os_str: &OsStr) {
     let test_vec = vec![os_str.to_os_string()];
     new_ucmd!().args(&test_vec).succeeds().stdout_is("fo<EFBFBD>o\n");

tests/by-util/test_relpath.rs

@@ -155,7 +155,7 @@ fn test_relpath_no_from_with_d() {
         at.mkdir_all(to);
 
         // d is part of subpath -> expect relative path
-        let mut result_stdout = scene
+        let _result_stdout = scene
             .ucmd()
             .arg(to)
             .arg(&format!("-d{}", pwd))
@@ -163,10 +163,10 @@ fn test_relpath_no_from_with_d() {
             .stdout_move_str();
         // relax rules for windows test environment
         #[cfg(not(windows))]
-        assert!(Path::new(&result_stdout).is_relative());
+        assert!(Path::new(&_result_stdout).is_relative());
 
         // d is not part of subpath -> expect absolut path
-        result_stdout = scene
+        let result_stdout = scene
             .ucmd()
             .arg(to)
             .arg("-dnon_existing")

tests/by-util/test_uname.rs

@@ -43,5 +43,5 @@ fn test_uname_kernel() {
     }
 
     #[cfg(not(target_os = "linux"))]
-    let result = ucmd.arg("-o").succeeds();
+    ucmd.arg("-o").succeeds();
 }