xfs: remove struct xfs_dabuf and infrastructure

The struct xfs_dabuf now only tracks a single xfs_buf and all the
information it holds can be gained directly from the xfs_buf. Hence
we can remove the struct dabuf and pass the xfs_buf around
everywhere.

Kill the struct dabuf and the associated infrastructure.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>

diff --git a/fs/xfs/xfs_dir2.c b/fs/xfs/xfs_dir2.c
index 67a250c36..b26a50f 100644
--- a/fs/xfs/xfs_dir2.c
+++ b/fs/xfs/xfs_dir2.c
@@ -592,7 +592,7 @@
 xfs_dir2_shrink_inode(
 	xfs_da_args_t	*args,
 	xfs_dir2_db_t	db,
-	xfs_dabuf_t	*bp)
+	struct xfs_buf	*bp)
 {
 	xfs_fileoff_t	bno;		/* directory file offset */
 	xfs_dablk_t	da;		/* directory file offset */
@@ -634,7 +634,7 @@
 	/*
 	 * Invalidate the buffer from the transaction.
 	 */
-	xfs_da_binval(tp, bp);
+	xfs_trans_binval(tp, bp);
 	/*
 	 * If it's not a data block, we're done.
 	 */