Gpu bufferfield fix
Some small changes in the calculation of the field sizes to allow only buffered fields as well as only absolute access fields. This is needed to allow AA-pattern and communication hiding for sparse kernels (ListLBM)
Some small changes in the calculation of the field sizes to allow only buffered fields as well as only absolute access fields. This is needed to allow AA-pattern and communication hiding for sparse kernels (ListLBM)
