xfs: Remove type argument from xfs_seek_data()/xfs_seek_hole()

The type is already indicated by the function naming explicitly, so this argument
can be omitted from those calls.

Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>