Remove unused logger dependency

* VuFindSearch/Service.php ($logger, setLogger, log): Remove unused
logger dependency.
* ../Module.php (setup): Dto.

module/VuFindSearch/Module.php

@@ -101,9 +101,6 @@ class Module
     public function setup(ServiceManager $sm)
     {
         $service = new Service();
-        if ($sm->has('VuFind\Logger')) {
-            $service->setLogger($sm->get('VuFind\Logger'));
-        }
         return $service;
     }
 }
\ No newline at end of file

module/VuFindSearch/src/VuFindSearch/Service.php

@@ -33,7 +33,6 @@ use VuFindSearch\Backend\BackendInterface;
 use VuFindSearch\Feature\RetrieveBatchInterface;
 use VuFindSearch\Backend\Exception\BackendException;
 
-use Zend\Log\LoggerInterface;
 use Zend\EventManager\EventManagerInterface;
 use Zend\EventManager\EventManager;
 
@@ -65,13 +64,6 @@ class Service
      */
     protected $events;
 
-    /**
-     * Logger, if any.
-     *
-     * @var LoggerInterface
-     */
-    protected $logger;
-
     /**
      * Cache resolved backends.
      *
@@ -226,18 +218,6 @@ class Service
         return $response;
     }
 
-    /**
-     * Set application logger.
-     *
-     * @param LoggerInterface $logger Logger
-     *
-     * @return void
-     */
-    public function setLogger(LoggerInterface $logger)
-    {
-        $this->logger = $logger;
-    }
-
     /**
      * Set EventManager instance.
      *
@@ -342,19 +322,4 @@ class Service
         $this->getEventManager()->trigger(self::EVENT_POST, $response, $args);
     }
 
-    /**
-     * Send a message to the logger.
-     *
-     * @param string $level   Log level
-     * @param string $message Log message
-     * @param array  $context Log context
-     *
-     * @return void
-     */
-    protected function log($level, $message, array $context = array())
-    {
-        if ($this->logger) {
-            $this->logger->$level($message, $context);
-        }
-    }
 }
\ No newline at end of file