Auto merge of #19970 - janczer:change_debug_assertions, r=emilio

Change debug assertions to specific ones

<!-- Please describe your changes on the following line: -->

---
<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `__` with appropriate data: -->
- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix #19962 (github issue number if applicable).

<!-- Also, please make sure that "Allow edits from maintainers" checkbox is checked, so that we can help you if you get stuck somewhere along the way.-->

<!-- Pull requests that do not address these steps are welcome, but they will require additional verification as part of the review process. -->

<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/19970)
<!-- Reviewable:end -->

components/style/properties/helpers.mako.rs

@@ -303,7 +303,7 @@
                     DeclaredValue::Value(value)
                 },
                 PropertyDeclaration::CSSWideKeyword(ref declaration) => {
-                    debug_assert!(declaration.id == LonghandId::${property.camel_case});
+                    debug_assert_eq!(declaration.id, LonghandId::${property.camel_case});
                     DeclaredValue::CSSWideKeyword(declaration.keyword)
                 },
                 PropertyDeclaration::WithVariables(..) => {