[XFS] remove unused filp from ioctl functions

SGI-PV: 959140
SGI-Modid: xfs-linux-melb:xfs-kern:27712a

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