xfs: Remove the macro XFS_BUF_PTR

Remove the definition and usages of the macro XFS_BUF_PTR.

Signed-off-by: Chandra Seetharaman <sekharan@us.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
diff --git a/fs/xfs/xfs_btree.h b/fs/xfs/xfs_btree.h
index 8d05a6a..5b240de 100644
--- a/fs/xfs/xfs_btree.h
+++ b/fs/xfs/xfs_btree.h
@@ -262,7 +262,7 @@
 /*
  * Convert from buffer to btree block header.
  */
-#define	XFS_BUF_TO_BLOCK(bp)	((struct xfs_btree_block *)XFS_BUF_PTR(bp))
+#define	XFS_BUF_TO_BLOCK(bp)	((struct xfs_btree_block *)((bp)->b_addr))
 
 
 /*