[XFS] Remove unused ilen variable and references.

SGI-PV: 907752
SGI-Modid: xfs-linux-melb:xfs-kern:28344a

Signed-off-by: Tim Shimmin <tes@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: Eric Sandeen <sandeen@sandeen.net>