Fix lint doc

Co-Authored-By: gnieto <[email protected]>

Author: mikerite

clippy_lints/src/slow_vector_initialization.rs

@@ -22,7 +22,7 @@ use crate::rustc_errors::{Applicability};
 /// **What it does:** Checks slow zero-filled vector initialization
 ///
 /// **Why is this bad?** This structures are non-idiomatic and less efficient than simply using
-/// `vec![len; 0]`.
+/// `vec![0; len]`.
 ///
 /// **Known problems:** None.
 ///