Rename private field to avoid multiple name clashes with fields and parameters

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/compress/trunk@1552769 13f79535-47bb-0310-9956-ffa450edef68
Remove some unnecessary parentheses.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/compress/trunk@1552770 13f79535-47bb-0310-9956-ffa450edef68