GIANT from VFS. In addition, disconnect also netncp, which is a base
requirement for NWFS.
In the possibility of a future maintenance of the code and later
readd to the FreeBSD base, maybe we should think about a better location
for netncp. I'm not entirely sure the / top location is actually right,
however I will let network people to comment on that more specifically.
This is not targeted for MFC.