hwpmc amd_pcpu_fini: fix a bug in code locked under DEBUG
hwpmc amd_pcpu_fini: fix a bug in code locked under DEBUG

MFC after:	16 days

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