Initial genotype for testing should be done with a single work-item
When `DEBUG_INITIAL_2BRT` is enabled, then initialize `genotype` using a single work-item. [This was initially set using all work-items](https://git.esa.informatik.tu-darmstadt.de/docking/ocladock/blob/169ca1f5eafba3c1701733a6b9c053330ffa851b/device/kernel_sd.cl#L169), but it is not necessary.
issue