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_dinode.h b/fs/xfs/xfs_dinode.h
index dffba9b..a372163 100644
--- a/fs/xfs/xfs_dinode.h
+++ b/fs/xfs/xfs_dinode.h
@@ -148,7 +148,7 @@
 		be32_to_cpu((dip)->di_nextents) : \
 		be16_to_cpu((dip)->di_anextents))
 
-#define	XFS_BUF_TO_DINODE(bp)	((xfs_dinode_t *)XFS_BUF_PTR(bp))
+#define	XFS_BUF_TO_DINODE(bp)	((xfs_dinode_t *)((bp)->b_addr))
 
 /*
  * For block and character special files the 32bit dev_t is stored at the