Fix signature of the UseControllerWork to respect WorkerInterface

Bug related to https://github.com/kriswallsmith/assetic/commit/01d4d8355b7541475985bf1c1fd54edd6eac57aa

PHP Fatal error:  Declaration of Symfony\Bundle\AsseticBundle\Factory\Worker\UseControllerWorker::process() must be compatible with Assetic\Factory\Worker\WorkerInterface::process(Assetic\Asset\AssetInterface $asset, Assetic\Factory\AssetFactory $factory)