ksud: fix issues found by clippy (#167)

These issues are mostly found by `cargo clippy -- -W clippy::pedantic`.

userspace/ksud/src/restorecon.rs

@@ -1,33 +1,37 @@
-use anyhow::{Context, Ok, Result};
-#[cfg(target_os = "android")]
-use extattr::{setxattr, Flags as XattrFlags};
+use anyhow::Result;
 use jwalk::{Parallelism::Serial, WalkDir};
 
+#[cfg(unix)]
+use anyhow::{Context, Ok};
+#[cfg(unix)]
+use extattr::{setxattr, Flags as XattrFlags};
+
 const SYSTEM_CON: &str = "u:object_r:system_file:s0";
 const _ADB_CON: &str = "u:object_r:adb_data_file:s0";
 
 pub fn setcon(path: &str, con: &str) -> Result<()> {
-    #[cfg(target_os = "android")]
+    #[cfg(unix)]
     setxattr(path, "security.selinux", con, XattrFlags::empty())
         .with_context(|| format!("Failed to change SELinux context for {path}"))?;
     Ok(())
 }
 
+#[cfg(unix)]
 pub fn setsyscon(path: &str) -> Result<()> {
     setcon(path, SYSTEM_CON)
 }
 
+#[cfg(not(unix))]
+pub fn setsyscon(_path: &str) -> Result<()> {
+    unimplemented!()
+}
+
 pub fn restore_syscon(dir: &str) -> Result<()> {
     for dir_entry in WalkDir::new(dir).parallelism(Serial) {
         if let Some(path) = dir_entry.ok().map(|dir_entry| dir_entry.path()) {
-            #[cfg(target_os = "android")]
+            #[cfg(unix)]
             setxattr(&path, "security.selinux", SYSTEM_CON, XattrFlags::empty()).with_context(
-                || {
-                    format!(
-                        "Failed to change SELinux context for {}",
-                        path.to_str().unwrap()
-                    )
-                },
+                || format!("Failed to change SELinux context for {}", path.display()),
             )?;
         }
     }