Merge pull request #2368 from spicyj/use-the-string

Fix warning message for using React.DOM.* as type

src/core/ReactLegacyElement.js

@@ -74,7 +74,7 @@ function warnForNonLegacyFactory(type) {
   warning(
     false,
     'Do not pass React.DOM.' + type.type + ' to JSX or createFactory. ' +
-    'Use the string "' + type + '" instead.'
+    'Use the string "' + type.type + '" instead.'
   );
 }