stdbuf: use .with_capacity for Vec storing searched paths

src/uu/stdbuf/src/stdbuf.rs

@@ -154,7 +154,7 @@ fn get_preload_env(_tmp_dir: &TempDir) -> UResult<(String, PathBuf)> {
     // Search paths in order:
     // 1. Directory where stdbuf is located (program_path)
     // 2. Compile-time directory from LIBSTDBUF_DIR
-    let mut search_paths: Vec<PathBuf> = Vec::new();
+    let mut search_paths: Vec<PathBuf> = Vec::with_capacity(2);
 
     // First, try to get the directory where stdbuf is running from
     if let Ok(exe_path) = std::env::current_exe() {