FFT set-up fixes
FFT set-up fixes

Turns out setting up FFTs is a lot less obvious than it would seem...
We need to un-set compatability mode, or cuFFT just will just flat-out
ignore the data format we have specified.

Also fixed some pointer arithmetic. Oops.

SKA-ScienceDataProcessor/RC,SKA-ScienceDataProcessor/RC,SKA-ScienceDataProcessor/RC,SKA-ScienceDataProcessor/RC,SKA-ScienceDataProcessor/RC