When compiled with -DDEBUG, only print the old value of a PMC in a debugging message if the flag PMC_F_OLDVALUE was specified in the PMC_OP_RW request being acted upon.  This should fix Coverity bug CID 671.
When compiled with -DDEBUG, only print the old value of a PMC in a
debugging message if the flag PMC_F_OLDVALUE was specified in the
PMC_OP_RW request being acted upon.  This should fix Coverity bug
CID 671.

Found by:	Coverity Prevent
MFC after:	3 weeks

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase