[gimp] app: fix segfault in previous commit

[Michael Natterer <mitch src gnome org>]

commit 1ff7ecb4aa6d8238bd76d404e90efcf0ce31abf5
Author: Ãyvind KolÃs <pippin gimp org>
Date:   Fri Mar 16 01:14:13 2012 +0000

    app: fix segfault in previous commit

 app/core/gimpprojection-construct.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)
---
diff --git a/app/core/gimpprojection-construct.c b/app/core/gimpprojection-construct.c
index 696ee7b..27ed9d1 100644
--- a/app/core/gimpprojection-construct.c
+++ b/app/core/gimpprojection-construct.c
@@ -256,8 +256,9 @@ gimp_projection_initialize (GimpProjection *proj,
 
       if (proj->use_gegl)
         {
-          g_assert (proj->sink_node);
-          gegl_node_get (proj->sink_node, "buffer", &buffer, NULL);
+          /* GEGL should really do this for us... */
+          gegl_node_get (gimp_projection_get_sink_node (proj),
+                         "buffer", &buffer, NULL);
         }
       else
         {