nfsctl: use vfs_path_lookup

nfsctl: use vfs_path_lookup

use vfs_path_lookup instead of open-coding the necessary functionality.

Signed-off-by: Josef 'Jeff' Sipek <jsipek@cs.sunysb.edu>
Acked-by: NeilBrown <neilb@suse.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>