zink: use OpFUnordNotEqual for nir_op_fne

we want to detect NaNs here, and OpFUnordNotEqual is the variant which does this

Reviewed-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5562>
1 file changed