Incorrect data format was selected when using CPU data transfers in
OpenXR. It always used `GPU_DATA_HALF_FLOAT`, also when the swapchains
where `GPU_RGBA8`. This resulted in black screens in release mode, and
asserts in debud mode.
Fixed by selecting the correct data transfer data type based on the
swapchain format.
Co-authored-by: jeroen@blender.org <Jeroen Bakker>
Pull Request: https://projects.blender.org/blender/blender/pulls/137269
b65b6febb9