xfs: port ondisk structure checks from xfs/122 to the kernel

Check this with every kernel and userspace build, so we can drop the
nonsense in xfs/122.  Roughly drafted with:

sed -e 's/^offsetof/\tXFS_CHECK_OFFSET/g' \
	-e 's/^sizeof/\tXFS_CHECK_STRUCT_SIZE/g' \
	-e 's/ = \([0-9]*\)/,\t\t\t\1);/g' \
	-e 's/xfs_sb_t/struct xfs_dsb/g' \
	-e 's/),/,/g' \
	-e 's/xfs_\([a-z0-9_]*\)_t,/struct xfs_\1,/g' \
	< tests/xfs/122.out | sort

and then manual fixups.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>