[XFS] All xfs_disk_dquot_t values are (as the name says) disk endian.

Before putting them into struct statfs they should be endian-swapped.

SGI-PV: 954580
SGI-Modid: xfs-linux-melb:xfs-kern:26550a

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nathan Scott <nathans@sgi.com>