the preallocate syscall will call the preallocate filesystem hook, if available. fix #6285 Change-Id: Ifff4595548610c8e009d4e5ffb64c37e0884e62d Reviewed-on: https://review.haiku-os.org/c/haiku/+/3382 Reviewed-by: Jérôme Duval <jerome.duval@gmail.com>