Cleanup macro matching recovery

The retry has been implemented already.

compiler/rustc_expand/src/mbe/macro_rules.rs

@@ -495,7 +495,6 @@ fn try_match_macro<'matcher, T: Tracker<'matcher>>(
     // hacky, but speeds up the `html5ever` benchmark significantly. (Issue
     // 68836 suggests a more comprehensive but more complex change to deal with
     // this situation.)
-    // FIXME(Nilstrieb): Stop recovery from happening on this parser and retry later with recovery if the macro failed to match.
     let parser = parser_from_cx(sess, arg.clone(), T::recovery());
     // Try each arm's matchers.
     let mut tt_parser = TtParser::new(name);