[XFS] hole not shown when file is created with resvsp

SGI-PV: 967674
SGI-Modid: xfs-linux-melb:xfs-kern:29211a

Signed-off-by: Vlad Apostolov <vapo@sgi.com>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>