The issue is caused by the fact that when both compositors are used,
`fftwf_plan_dft_r2c_2d` can end up being called in parallel, which is
only thread-safe if `fftwf_make_planner_thread_safe` is called before.
This is done by `fftw::initialize_float`, but only if the FFTW threading
support library is available. Said library was not detected correctly on
Windows because of a typo, which this change addresses. This should also
make the fog glow faster on Windows because it'll now use multithreaded
FFT as intended.
This change also moves the call to `initialize_float` to the main
function because the FFTW functions it calls are not thread-safe and
because FFTW is also used by Audaspace, which cannot call it.
Pull Request: https://projects.blender.org/blender/blender/pulls/136557
Jorn Visser
812529d215