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_trans_buf.c b/fs/xfs/xfs_trans_buf.c
index 1bc04d4..f9f1bf6 100644
--- a/fs/xfs/xfs_trans_buf.c
+++ b/fs/xfs/xfs_trans_buf.c
@@ -194,7 +194,7 @@
 		return NULL;
 	}
 
-	ASSERT(!XFS_BUF_GETERROR(bp));
+	ASSERT(!bp->b_error);
 
 	_xfs_trans_bjoin(tp, bp, 1);
 	trace_xfs_trans_get_buf(bp->b_fspriv);
@@ -293,10 +293,10 @@
 			return (flags & XBF_TRYLOCK) ?
 					EAGAIN : XFS_ERROR(ENOMEM);
 
-		if (XFS_BUF_GETERROR(bp) != 0) {
+		if (bp->b_error) {
+			error = bp->b_error;
 			xfs_ioerror_alert("xfs_trans_read_buf", mp,
 					  bp, blkno);
-			error = XFS_BUF_GETERROR(bp);
 			xfs_buf_relse(bp);
 			return error;
 		}
@@ -330,7 +330,7 @@
 		ASSERT(xfs_buf_islocked(bp));
 		ASSERT(bp->b_transp == tp);
 		ASSERT(bp->b_fspriv != NULL);
-		ASSERT((XFS_BUF_ISERROR(bp)) == 0);
+		ASSERT(!bp->b_error);
 		if (!(XFS_BUF_ISDONE(bp))) {
 			trace_xfs_trans_read_buf_io(bp, _RET_IP_);
 			ASSERT(!XFS_BUF_ISASYNC(bp));
@@ -386,10 +386,9 @@
 		return (flags & XBF_TRYLOCK) ?
 					0 : XFS_ERROR(ENOMEM);
 	}
-	if (XFS_BUF_GETERROR(bp) != 0) {
-	    XFS_BUF_SUPER_STALE(bp);
-		error = XFS_BUF_GETERROR(bp);
-
+	if (bp->b_error) {
+		error = bp->b_error;
+		XFS_BUF_SUPER_STALE(bp);
 		xfs_ioerror_alert("xfs_trans_read_buf", mp,
 				  bp, blkno);
 		if (tp->t_flags & XFS_TRANS_DIRTY)