NULL.

Patch provided by Eric Sandeen.

SGI-PV: 961693
SGI-Modid: xfs-linux-melb:xfs-kern:28199a
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>