[gegl] video-degradataion: fix to opencl misbehavior by jan vesely

[Øyvind Kolås <ok src gnome org>]

commit 734a53526bb90b37370ee01eb28c1747590d6ebf
Author: Øyvind Kolås <pippin gimp org>
Date:   Sun May 15 14:06:36 2016 +0200

    video-degradataion: fix to opencl misbehavior by jan vesely

 operations/common/video-degradation.c |   17 ++++++++++-------
 1 files changed, 10 insertions(+), 7 deletions(-)
---
diff --git a/operations/common/video-degradation.c b/operations/common/video-degradation.c
index 29197ff..e01e050 100644
--- a/operations/common/video-degradation.c
+++ b/operations/common/video-degradation.c
@@ -201,13 +201,16 @@ cl_process (GeglOperation       *operation,
   const size_t gbl_size[2] = {roi->width, roi->height};
   const size_t gbl_off[2]  = {roi->x, roi->y};
   cl_int cl_err = 0;
+  cl_mem filter_pat = NULL;
 
-  cl_mem filter_pat = gegl_clCreateBuffer (gegl_cl_get_context (),
-                                           CL_MEM_READ_ONLY | CL_MEM_COPY_HOST_PTR,
-                                           pattern_width[o->pattern] *
-                                           pattern_height[o->pattern] * sizeof(cl_int),
-                                           (void*)pattern[o->pattern],
-                                           &cl_err);
+  if (!cl_data)
+    goto error;
+  filter_pat = gegl_clCreateBuffer (gegl_cl_get_context (),
+                                    CL_MEM_READ_ONLY | CL_MEM_COPY_HOST_PTR,
+                                    pattern_width[o->pattern] *
+                                    pattern_height[o->pattern] * sizeof(cl_int),
+                                    (void*)pattern[o->pattern],
+                                    &cl_err);
   CL_CHECK;
   cl_err = gegl_cl_set_kernel_args (cl_data->kernel[0],
                                     sizeof(cl_mem), &in_buf,