B44 tables not initialized when decoding B44A

[azeno]

I noticed after upgrading from 3.3 to 3.4 that loading B44A compressed files resulted in empty textures. After writing a B44A file the reads started to work. After digging a bit in the sources it seems to me the internal_exr_undo_b44a function is simply missing a call to exrcore_ensure_b44_tables?

[cary-ilm]

Thanks for the detective work, that's tricky. I submitted #2451 to add the missing initialization.