Remove loggerFactory, it's part of the included Trait.

src/Plugin/Field/FieldFormatter/BgImgFieldFormatter.php

@@ -3,7 +3,6 @@
 namespace Drupal\bg_img_field\Plugin\Field\FieldFormatter;
 
 use Drupal\Core\Cache\Cache;
-use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Entity\EntityStorageInterface;
 use Drupal\Core\Entity\EntityTypeManagerInterface;
 use Drupal\Core\Field\FieldDefinitionInterface;
@@ -12,7 +11,6 @@ use Drupal\Core\File\FileSystemInterface;
 use Drupal\Core\File\FileUrlGeneratorInterface;
 use Drupal\Core\Form\FormStateInterface;
 use Drupal\Core\Image\ImageFactory;
-use Drupal\Core\Logger\LoggerChannelFactoryInterface;
 use Drupal\Core\Logger\LoggerChannelTrait;
 use Drupal\Core\Plugin\ContainerFactoryPluginInterface;
 use Drupal\Core\Routing\UrlGeneratorInterface;
@@ -42,11 +40,6 @@ use Symfony\Component\HttpFoundation\RequestStack;
  */
 class BgImgFieldFormatter extends ResponsiveImageFormatter implements ContainerFactoryPluginInterface {
 
-  /**
-   * Logger channel trait.
-   *
-   * @var Drupal\Core\Logger\LoggerChannelTrait
-   */
   use LoggerChannelTrait;
 
   /**
@@ -77,13 +70,6 @@ class BgImgFieldFormatter extends ResponsiveImageFormatter implements ContainerF
    */
   protected $requestStack;
 
-  /**
-   * The Logger Channel Factory service.
-   *
-   * @var \Drupal\Core\Logger\LoggerChannelFactoryInterface
-   */
-  protected $loggerFactory;
-
   /**
    * The Breakpoint Manager service.
    *
@@ -148,8 +134,6 @@ class BgImgFieldFormatter extends ResponsiveImageFormatter implements ContainerF
    *   The token service used to generate tokens.
    * @param \Symfony\Component\HttpFoundation\RequestStack $request_stack
    *   The request stack for the current request context.
-   * @param \Drupal\Core\Logger\LoggerChannelFactoryInterface $logger_factory
-   *   The logger channel factory for logging errors.
    * @param \Drupal\Core\Url\UrlGeneratorInterface $url_generator
    *   The URL generator for generating URLs for routes.
    * @param \Drupal\Core\File\FileUrlGeneratorInterface $file_url_generator
@@ -174,7 +158,6 @@ class BgImgFieldFormatter extends ResponsiveImageFormatter implements ContainerF
     ImageFactory $imageFactory,
     Token $token_service,
     RequestStack $request_stack,
-    LoggerChannelFactoryInterface $logger_factory,
     UrlGeneratorInterface $url_generator,
     FileUrlGeneratorInterface $file_url_generator,
     EntityTypeManagerInterface $entityTypeManager,
@@ -193,7 +176,6 @@ class BgImgFieldFormatter extends ResponsiveImageFormatter implements ContainerF
       $current_user
     );
 
-    $this->logger = $this->getLogger('bg_img_field');
     $this->entityTypeManager = $entityTypeManager;
     $this->fileSystem = $fileSystem;
     $this->entityTypeManager = $entityTypeManager;
@@ -226,7 +208,6 @@ class BgImgFieldFormatter extends ResponsiveImageFormatter implements ContainerF
       $container->get('image.factory'),
       $container->get('token'),
       $container->get('request_stack'),
-      $container->get('logger.factory'),
       $container->get('url_generator'),
       $container->get('file_url_generator'),
       $container->get('entity_type.manager')
@@ -391,7 +372,7 @@ class BgImgFieldFormatter extends ResponsiveImageFormatter implements ContainerF
     if (!$responsive_image_style) {
       $field_definition = $this->fieldDefinition->getFieldStorageDefinition();
 
-      $this->logger->error('
+      $this->getLogger('bg_img_field')->error('
         There is no responsive image style set for the {field_name} field on the {entity_type} entity. Please ensure
         that the responsive image style is configured at <a href="{link}">{link}</a>.  Then set the correct style on the
         formatter for the entity display.