Error in symfony when accessing getParameter

I'm immersed in a project in symfony and I'm doing some tests with different bundles.

In the first CatalogBundle bundle, it is responsible for managing two entities, Producto and Proveedor with their respective form and so on. When I add a provider, I keep their image in a directory. In this bundle I add an event that has been removed by a provider supplier_deleted .

In the second FileManagerBundle bundle, you have an event listener that listens for a supplier_deleted event. If so, delete the associated image.

When I try to do it, symfony returns the error

  

Call to a member function getParameter () on null

This is the code of FileManagerBundleController

namespace FileManagerBundle\Controller;

use Symfony\Bundle\FrameworkBundle\Controller\Controller;

class FileManagerController extends Controller
{

    public function deleteSupplierImage (Supplier $supplier)
    {
        $supplierImage = $supplier->getLogo();
        unlink($this->getParameter('kernel.root_dir').'/../web/uploads/suppliers/'.$supplierImage);
    }
}

FileManagerBundle \ Resources \ config \ services.yml

services:
    FileManagerBundle.FileManagerController:
        class: FileManagerBundle\Controller\FileManagerController
    FileManagerBundle.delete_supplier_image_event_listener:
        class: FileManagerBundle\EventListener\DeleteSupplierImageEventListener
        arguments:
            - "@FileManagerBundle.FileManagerController"
        tags:
            - { name: kernel.event_listener, event: supplier_deleted, method: deleteSupplierImage }

FileManagerExtension.php

namespace FileManagerBundle\DependencyInjection;

use Symfony\Component\DependencyInjection\Extension\Extension;
use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\DependencyInjection\Loader\YamlFileLoader;
use Symfony\Component\Config\FileLocator;

class FileManagerExtension extends Extension
{
    public function load(array $configs, ContainerBuilder $container)
    {
        $loader = new YamlFileLoader(
            $container,
            new FileLocator(__DIR__.'/../Resources/config/')
        );
        $loader->load('services.yml');
    }
}

Any idea what can be wrong?