xfs: Remove redundant error variable from xfs_growfs_data_private()

Commit eab4e633 "xfs: uncached buffer reads need to return an error".

Remove redundant error variable, using the function level error variable
to store bp->b_error instead.
Signed-off-by: NJie Liu <jeff.liu@oracle.com>
Reviewed-by: NBen Myers <bpm@sgi.com>
Signed-off-by: NBen Myers <bpm@sgi.com>

fs/xfs/xfs_fsops.c

@@ -176,7 +176,7 @@ xfs_growfs_data_private(
 	if (!bp)
 		return EIO;
 	if (bp->b_error) {
-		int	error = bp->b_error;
+		error = bp->b_error;
 		xfs_buf_relse(bp);
 		return error;
 	}