xfs: move the di_extsize field to struct xfs_inode

In preparation of removing the historic icinode struct, move the extsize
field into the containing xfs_inode structure.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index b2009f9..829df5c 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -2937,7 +2937,7 @@ xfs_bmap_add_extent_hole_real(
  */
 
 /*
- * Adjust the size of the new extent based on di_extsize and rt extsize.
+ * Adjust the size of the new extent based on i_extsize and rt extsize.
  */
 int
 xfs_bmap_extsize_align(