doesn't know about getvfsbyname() and the vfsconf structure. This
disables the -fstype option if compiled with a pre-processor that
defines __NetBSD__. With the FreeBSD built pre-processor, find can only
be built with the FreeBSD libc. So when running with a NetBSD kernel,
FreeBSD's libc will have to return ENOSYS for things that NetBSD
doesn't support. That's life in a hybrid world.