Remove no longer needed import

Author: Voultapher

src/librustdoc/html/highlight.rs

@@ -8,7 +8,6 @@
 use std::borrow::Cow;
 use std::collections::VecDeque;
 use std::fmt::{self, Display, Write};
-use std::format_args_nl;
 
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_lexer::{Cursor, FrontmatterAllowed, LiteralKind, TokenKind};