remove parentheses from around get_local_id et al
remove parentheses from around get_local_id et al

hughperkins/coriander,hughperkins/coriander,hughperkins/coriander,hughperkins/cuda-on-cl,hughperkins/cuda-on-cl,hughperkins/cuda-on-cl,hughperkins/cuda-on-cl,hughperkins/coriander