CRM-13302 - php 5.3 error fix

Error: Can't use function return value in write context in
/var/lib/jenkins/workspace/CiviCRM-4.3-WebTest-git/LABEL/ubuntu1204/SUITE/WebTest_AllTests/civicrm/CRM/Logging/Schema.php,
line 378

Note: this worked with php 5.5 & 5.4.