remove log member variable which is not used currently

git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1628208 13f79535-47bb-0310-9956-ffa450edef68
fix javadoc syntax error

git-svn-id: https://svn.apache.org/repos/asf/sling/trunk@1628209 13f79535-47bb-0310-9956-ffa450edef68