Fix stylecop in Microsoft.AspNet.Mvc

The new rule that's deactivated is for cases like this:

```
yield return describe.Transient<INestedProvider<ActionDescriptorProviderContext>,
                                ReflectedRouteConstraintsActionDescriptorProvider>();
```

It's too long of a line if you put it all together, but there's no good way to break it up that this rule is happy with, so we should chuck it out.