minor bug fix
minor bug fix

fvdnabee/mspsim,mspsim/mspsim,nfi/mspsim,cmorty/mspsim,fvdnabee/mspsim,contiki-os/mspsim,joakimeriksson/mspsim,cmorty/mspsim,ransford/mspsim,nfi/mspsim,mspsim/mspsim,joakimeriksson/mspsim,contiki-os/mspsim,ransford/mspsim