[CLEANUP] Added data type to doc comment

extensions/karma/Classes/Service/KarmaService.php

@@ -208,8 +208,8 @@ class KarmaService implements \TYPO3\CMS\Core\SingletonInterface
     /**
      * Trigger a karma-earning action for a user
      *
-     * @param $issuerCode The issuer code for the karma
-     * @param $issuerActionCode The issuer action code for the karma
+     * @param string $issuerCode The issuer code for the karma
+     * @param string $issuerActionCode The issuer action code for the karma
      * @param ExtbaseFrontendUser $frontendUser The frontend user earning the karma
      * @throws \Exception If the $issuerCode, $issuerActionCode, or karma source code is not defined in TypoScript.
      */