(mvc) some style fixes in ApiMutableModelControllerBase.php from...

(mvc) some style fixes in ApiMutableModelControllerBase.php from https://github.com/opnsense/core/pull/1134

src/opnsense/mvc/app/controllers/OPNsense/Base/ApiMutableModelControllerBase.php

@@ -164,7 +164,6 @@ abstract class ApiMutableModelControllerBase extends ApiControllerBase
      * setAction is called. This hook is called after a model has been
      * constructed and validated but before it serialized to the configuration
      * and written to disk
-     * @param $mdl The validated model containing the new state of the model
      * @return Error message on error, or null/void on success
      */
     protected function setActionHook()
@@ -184,9 +183,9 @@ abstract class ApiMutableModelControllerBase extends ApiControllerBase
             $mdl->setNodes($this->request->getPost(static::$internalModelName));
             $result = $this->validate();
             if (empty($result['result'])) {
-                $errorMessage = $this->setActionHook();
-                if (!empty($errorMessage)) {
-                    $result['error'] = $errorMessage;
+                $hookErrorMessage = $this->setActionHook();
+                if (!empty($hookErrorMessage)) {
+                    $result['error'] = $hookErrorMessage;
                 } else {
                     return $this->save();
                 }