[kernel] remove compiler warning
[kernel] remove compiler warning

bremond/siconos,bremond/siconos,siconos/siconos,radarsat1/siconos,fperignon/siconos,fperignon/siconos,fperignon/siconos,radarsat1/siconos,bremond/siconos,bremond/siconos,fperignon/siconos,radarsat1/siconos,radarsat1/siconos,fperignon/siconos,siconos/siconos,radarsat1/siconos,siconos/siconos,bremond/siconos,siconos/siconos