- Don't specify vnode operations for mknod, lease, and advlock--let them
fall through to vop_default.
- Implement vop_default with &default_vnodeops, rather than with VOP_PANIC,
so that unimplemented vnode operations are handled in more sensible ways
than panicking, such as EOPNOTSUPP on ACL queries generated by bsdtar,
or mknod.
MFC after: 3 days