Used existing class instance creation function

Author: CrashSensei

src/CleanActivitylogCommand.php

@@ -30,8 +30,7 @@ public function handle()
 
         $cutOffDate = Carbon::now()->subDays($maxAgeInDays)->format('Y-m-d H:i:s');
 
-        $activityModelClass = '\\' . ActivitylogServiceProvider::getActivityModelClass();
-        $activity = new $activityModelClass;
+        $activity = ActivitylogServiceProvider::getActivityModelInstance();
         $amountDeleted = $activity->where('created_at', '<', $cutOffDate)->delete();
 
         $this->info("Deleted {$amountDeleted} record(s) from the activity log.");