src/include/pcp/pmapi.h: change macro for pm{Get,Set}DerivedControl
src/include/pcp/pmapi.h: change macro for pm{Get,Set}DerivedControl

Change macro from PCP_DERIVED_DEBUG_PMNS to PCP_DERIVED_DEBUG_EVAL
to better capture debugging instrumentation scope.

adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp,adfernandes/pcp