[buffer] More error handling

Should be all set now.
diff --git a/src/hb-buffer-private.hh b/src/hb-buffer-private.hh
index 6954f96..7c298b0 100644
--- a/src/hb-buffer-private.hh
+++ b/src/hb-buffer-private.hh
@@ -95,9 +95,9 @@
 
   /* Buffer contents */
 
+  bool in_error; /* Allocation failed */
   bool have_output; /* Whether we have an output buffer going on */
   bool have_positions; /* Whether we have positions */
-  bool in_error; /* Allocation failed */
 
   unsigned int i; /* Cursor into ->info and ->pos arrays */
   unsigned int len; /* Length of ->info and ->pos arrays */