writerfilter: Consistent naming of dmapper_logger.

Change-Id: I229c8c9fa08827a15404bf0851b7c27771f35706
writerfilter: Fold all the various DEBUG_* macros into DEBUG_DOMAINMAPPER.

They were set either all, or none anyway.

Change-Id: I4893ff5fef7c1a472ee8889ad36db2c3d3734be6