In preparation of removing the historic icinode struct, move the
cowextsize field into the containing xfs_inode structure.  Also
switch to use the xfs_extlen_t instead of a uint32_t.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>