Fix a mixin name in a blog post

_posts/2016-03-07-react-v15-rc1.md

@@ -73,7 +73,7 @@ These deprecations were introduced in v0.14 with a warning and the APIs are now
 
 Each of these changes will continue to work as before with a new warning until the release of React 16 so you can upgrade your code gradually.
 
-- `LinkedValueMixin` and `valueLink` are now deprecated due to very low popularity. If you need this, you can use a wrapper component that implements the same behavior: [react-linked-input](https://www.npmjs.com/package/react-linked-input).
+- `LinkedStateMixin` and `valueLink` are now deprecated due to very low popularity. If you need this, you can use a wrapper component that implements the same behavior: [react-linked-input](https://www.npmjs.com/package/react-linked-input).
 
 
 ### New helpful warnings