addition of -Werror broke the old build

Before RE switching to the new-infra build for JCE provider binary, we unfortunately still have to deal with old build.

The old build fails after the several fixes in other components makefile which added "-Xlint:all -Werror", e.g.
JDK-7122061: add -Xlint:all -Werror to warning-free build steps

Need to fix various classes in order to buid JCE successfully using the old build process.