[gimp] app: migrate operationbuffersourcevalidate to new iterator api

[Øyvind "pippin" Kolås <ok src gnome org>]

commit 95358ca1fafb1865d3b7040198ec53e7769506e6
Author: Øyvind Kolås <pippin gimp org>
Date:   Tue Sep 11 01:46:10 2018 +0200

    app: migrate operationbuffersourcevalidate to new iterator api

 app/operations/gimpoperationbuffersourcevalidate.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/app/operations/gimpoperationbuffersourcevalidate.c 
b/app/operations/gimpoperationbuffersourcevalidate.c
index 85a87ecd8b..40b16871e4 100644
--- a/app/operations/gimpoperationbuffersourcevalidate.c
+++ b/app/operations/gimpoperationbuffersourcevalidate.c
@@ -18,6 +18,7 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
+#define GEGL_ITERATOR2_API
 #include "config.h"
 
 #include <cairo.h>
@@ -317,7 +318,7 @@ gimp_operation_buffer_source_validate_process (GeglOperation        *operation,
                                                                    rect.height),
                                                    level, NULL,
                                                    GEGL_BUFFER_READ,
-                                                   GEGL_ABYSS_NONE);
+                                                   GEGL_ABYSS_NONE, 1);
 
                   while (gegl_buffer_iterator_next (iter));
                 }