TAKE - fix kNFSD operation

[hch@xxxxxxxxxxxxxxxxxxxxx]

Thanks to Kazuhisa TAKEI at NEC for reminding me of this again and
submitting an alternative patch.

This is a different version I used to test the refcache performance,
it goes through VFS_VGET to avoid code duplication and tries to
follow the 2.4 linvfs_fh_to_dentry as much as possible.


Date:  Mon Oct 28 06:32:31 PST 2002
Workarea:  lab343.munich.sgi.com:/home/hch/repo/slinx/2.5.x-xfs

The following file(s) were checked into:
  bonnie.engr.sgi.com:/isms/slinx/2.5.x-xfs


Modid:  2.5.x-xfs:slinx:131214a
linux/fs/xfs/linux/xfs_super.c - 1.238
        - implement get_dentry export operation