MFC: r220764

MFC: r220764
Add a vput() to nfs_lookitup() in the experimental NFS client
for a case that will probably never happen. It can only
happen if a server were to successfully lookup a file, but not
return attributes for that file. Although technically allowed
by the NFSv3 RFC, I doubt any server would ever do this.
However, if it did, the client would have not vput()'d the
new vnode when it needed to do so.

git-svn-id: svn://svn.freebsd.org/base/stable/8@221311 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f