xfs: Remove the macro XFS_BUF_ERROR and family

Remove the definitions and usage of the macros XFS_BUF_ERROR,
XFS_BUF_GETERROR and XFS_BUF_ISERROR.

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_vnodeops.c b/fs/xfs/xfs_vnodeops.c
index 88d1214..3baebe2 100644
--- a/fs/xfs/xfs_vnodeops.c
+++ b/fs/xfs/xfs_vnodeops.c
@@ -83,7 +83,7 @@
 
 		bp = xfs_buf_read(mp->m_ddev_targp, d, BTOBB(byte_cnt),
 				  XBF_LOCK | XBF_MAPPED | XBF_DONT_BLOCK);
-		error = XFS_BUF_GETERROR(bp);
+		error = xfs_buf_geterror(bp);
 		if (error) {
 			xfs_ioerror_alert("xfs_readlink",
 				  ip->i_mount, bp, XFS_BUF_ADDR(bp));
@@ -1648,7 +1648,7 @@
 			byte_cnt = XFS_FSB_TO_B(mp, mval[n].br_blockcount);
 			bp = xfs_trans_get_buf(tp, mp->m_ddev_targp, d,
 					       BTOBB(byte_cnt), 0);
-			ASSERT(bp && !XFS_BUF_GETERROR(bp));
+			ASSERT(!xfs_buf_geterror(bp));
 			if (pathlen < byte_cnt) {
 				byte_cnt = pathlen;
 			}