Fixup indentation of `PhocRender`

I've worked a bit on the renderer and what kept distracting me was the mixed indent. With 0.30 out of the door and besides !463 (merged) no outstanding MRs in that area this could be a good point in time to fix this bit up. The actual render changes will be cooking a bit longer but having this out of the way would be good (otherwise I'd refrain from indentation only cleanups).

I've kept things at a minimum to get rid of tab vs spaces ignoring minor nits in other places.