message: return error code in case grp creation fails
diff: @@ -27,5 +27,5 @@ Int_t AliHLTCreateGRP(Int_t runNumber, TString detectorList, TString beamType, T
  int retVal = GrpBuilder->CreateGRP(runNumber, detectorList, beamType, runType, startShift, endShift, defaults);
  delete GrpBuilder;
  - return(retVal == 0 ? 2 : 0);
  + return(retVal == 0 ? 2 : -retVal);
  }
  