[cogl] Fix the check for whether snippets require pipeline to need blending

[Neil Roberts <nroberts src gnome org>]

commit 109c815bf747fe027a74f098b4fcb6ea4846a482
Author: Neil Roberts <neil linux intel com>
Date:   Fri Jun 21 11:27:42 2013 +0100

    Fix the check for whether snippets require pipeline to need blending
    
    When determining whether a pipeline needs blending, it was previously
    returning TRUE if the pipeline has no snippets, whereas it should be
    the other way around because we can't determine the final colour when
    there are snipets.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=702570
    
    Reviewed-by: Robert Bragg <robert linux intel com>

 cogl/cogl-pipeline.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/cogl/cogl-pipeline.c b/cogl/cogl-pipeline.c
index e843cd6..58eaacf 100644
--- a/cogl/cogl-pipeline.c
+++ b/cogl/cogl-pipeline.c
@@ -709,13 +709,13 @@ _cogl_pipeline_change_implies_transparency (CoglPipeline *pipeline,
 
   if (changes & COGL_PIPELINE_STATE_FRAGMENT_SNIPPETS)
     {
-      if (!_cogl_pipeline_has_non_layer_fragment_snippets (pipeline))
+      if (_cogl_pipeline_has_non_layer_fragment_snippets (pipeline))
         return TRUE;
     }
 
   if (changes & COGL_PIPELINE_STATE_VERTEX_SNIPPETS)
     {
-      if (!_cogl_pipeline_has_non_layer_vertex_snippets (pipeline))
+      if (_cogl_pipeline_has_non_layer_vertex_snippets (pipeline))
         return TRUE;
     }