Fix potential overflow issue with error messages in PlatformImp.cpp.
Fix potential overflow issue with error messages in PlatformImp.cpp.

Change-Id: I02339b56d429c8c7730697c6012fdb49ff0e15b4
Signed-off-by: Christopher M. Cantalupo <9cf3ecca60a3dd7112ab0e7250bedb8a752e3958@intel.com>

geopm/geopm,cmcantalupo/geopm,cmcantalupo/geopm,cmcantalupo/geopm,geopm/geopm,cmcantalupo/geopm,geopm/geopm,geopm/geopm,geopm/geopm,cmcantalupo/geopm