fix(mkdir): add feat_smack cfg alias

Author: xtqqczze

src/uu/mkdir/build.rs

@@ -8,5 +8,6 @@ use cfg_aliases::cfg_aliases;
 pub fn main() {
     cfg_aliases! {
         selinux: { all(feature = "feat_selinux", any(target_os = "android", target_os = "linux")) },
+        smack: { all(feature = "feat_smack", target_os = "linux") },
     }
 }

src/uu/mkdir/src/mkdir.rs

@@ -343,7 +343,7 @@ fn create_single_dir(path: &Path, is_parent: bool, config: &Config) -> UResult<(
             }
 
             // Apply SMACK context if requested
-            #[cfg(feature = "smack")]
+            #[cfg(smack)]
             if config.set_security_context {
                 uucore::smack::set_smack_label_and_cleanup(path, config.context, |p| {
                     std::fs::remove_dir(p)