Rollup merge of #136636 - bjorn3:error_cleanup, r=compiler-errors

Couple of minor cleanups to the diagnostic infrastructure

compiler/rustc_driver_impl/src/lib.rs

@@ -1024,7 +1024,7 @@ pub fn describe_flag_categories(early_dcx: &EarlyDiagCtxt, matches: &Matches) ->
     let wall = matches.opt_strs("W");
     if wall.iter().any(|x| *x == "all") {
         print_wall_help();
-        rustc_errors::FatalError.raise();
+        return true;
     }
 
     // Don't handle -W help here, because we might first load additional lints.