docs: add () after method names

Author: kenjis

user_guide_src/source/changelogs/v4.1.2.rst

@@ -59,7 +59,7 @@ Deprecations
 - Consolidated and deprecated ``ControllerResponse`` and ``FeatureResponse`` in favor of ``TestResponse``.
 - Deprecated ``Time::instance()``, use ``Time::createFromInstance()`` instead (now accepts ``DateTimeInterface``).
 - Deprecated ``IncomingRequest::removeRelativeDirectory()``, use ``URI::removeDotSegments()`` instead
-- Deprecated ``\API\ResponseTrait::failValidationError`` to use ``\API\ResponseTrait::failValidationErrors`` instead
+- Deprecated ``\API\ResponseTrait::failValidationError()`` to use ``\API\ResponseTrait::failValidationErrors()`` instead
 
 Bugs Fixed
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