NFS: Fix an Oops in encode_lookup()

NFS: Fix an Oops in encode_lookup()

2.6.22-stable review patch.  If anyone has any objections, please let us
know.

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From: Trond Myklebust <Trond.Myklebust@netapp.com>

mainline: 54af3bb543c071769141387a42deaaab5074da55

It doesn't look as if the NFS file name limit is being initialised correctly
in the struct nfs_server. Make sure that we limit whatever is being set in
nfs_probe_fsinfo() and nfs_init_server().

Also ensure that readdirplus and nfs4_path_walk respect our file name
limits.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Neil Brown <neilb@suse.de>
CC: Oliver Pinter <oliver.pntr@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Oliver Pinter <oliver.pntr@gmail.com>