Fix always failing assertion due to using incorrect element name

The object element in the document has "exposed_object_with_name" as the
name, but the assertion was checking for name "exposed_object". This
meant that this assertion would never ever be successful.

html/dom/documents/dom-tree-accessors/nameditem-names.html

@@ -52,7 +52,7 @@
 }, "An img name appears in a document's property names when the img has no id.");
 
 test(function() {
-  assert_true(names.includes("exposed_object"))
+  assert_true(names.includes("exposed_object_with_name"))
 }, "An object name appears in a document's property names if the object is exposed.");
 
 test(function() {