Update clippy_lints/src/format_args.rs

Co-authored-by: Cameron Steffen <cam.steffen94@gmail.com>

Author: smoelius

clippy_lints/src/format_args.rs

@@ -118,7 +118,7 @@ fn check_to_string_in_format_args<'tcx>(
     if_chain! {
         if let ExprKind::MethodCall(_, _, [receiver], span) = value.kind;
         if let Some(method_def_id) = cx.typeck_results().type_dependent_def_id(value.hir_id);
-        if match_def_path(cx, method_def_id, &paths::TO_STRING_METHOD);
+        if is_diag_trait_item(cx, method_def_id, sym::ToString);
         if let Some(receiver) = args.get(0);
         let ty = cx.typeck_results().expr_ty(receiver);
         if let Some(display_trait_id) = get_trait_def_id(cx, &paths::DISPLAY_TRAIT);