fs/nfs/nfsroot.c: remove CVS keyword

This patch removes a CVS keyword that wasn't updated for a long time
from a comment.
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/nfsroot.c

 /*
- *  $Id: nfsroot.c,v 1.45 1998/03/07 10:44:46 mj Exp $
- *
  *  Copyright (C) 1995, 1996  Gero Kuhlmann <gero@gkminix.han.de>
  *
  *  Allow an NFS filesystem to be mounted as root. The way this works is: