xfs: avoid usage of struct xfs_dir2_data

In most places we can simply pass around and use the struct xfs_dir2_data_hdr,
which is the first and most important member of struct xfs_dir2_data instead
of the full structure.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Alex Elder <aelder@sgi.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
diff --git a/fs/xfs/xfs_dir2_data.h b/fs/xfs/xfs_dir2_data.h
index efbc290..aa6bf91c 100644
--- a/fs/xfs/xfs_dir2_data.h
+++ b/fs/xfs/xfs_dir2_data.h
@@ -157,12 +157,10 @@
 #else
 #define	xfs_dir2_data_check(dp,bp)
 #endif
-extern xfs_dir2_data_free_t *xfs_dir2_data_freefind(xfs_dir2_data_t *d,
-				xfs_dir2_data_unused_t *dup);
-extern xfs_dir2_data_free_t *xfs_dir2_data_freeinsert(xfs_dir2_data_t *d,
+extern xfs_dir2_data_free_t *xfs_dir2_data_freeinsert(xfs_dir2_data_hdr_t *hdr,
 				xfs_dir2_data_unused_t *dup, int *loghead);
-extern void xfs_dir2_data_freescan(struct xfs_mount *mp, xfs_dir2_data_t *d,
-				int *loghead);
+extern void xfs_dir2_data_freescan(struct xfs_mount *mp,
+				xfs_dir2_data_hdr_t *hdr, int *loghead);
 extern int xfs_dir2_data_init(struct xfs_da_args *args, xfs_dir2_db_t blkno,
 				struct xfs_dabuf **bpp);
 extern void xfs_dir2_data_log_entry(struct xfs_trans *tp, struct xfs_dabuf *bp,