Remove method UserModel::getFullname()

app/Helper/UserHelper.php

@@ -50,7 +50,8 @@ class UserHelper extends Base
      */
     public function getFullname(array $user = array())
     {
-        return $this->userModel->getFullname(empty($user) ? $this->userSession->getAll() : $user);
+        $user = empty($user) ? $this->userSession->getAll() : $user;
+        return $user['name'] ?: $user['username'];
     }
 
     /**