doc/examples: make use of the parameter filters_descr parameter in init_filters().

doc/examples/filtering_audio.c

@@ -129,7 +129,7 @@ static int init_filters(const char *filters_descr)
     inputs->pad_idx    = 0;
     inputs->next       = NULL;
 
-    if ((ret = avfilter_graph_parse(filter_graph, filter_descr,
+    if ((ret = avfilter_graph_parse(filter_graph, filters_descr,
                                     &inputs, &outputs, NULL)) < 0)
         return ret;
 

doc/examples/filtering_video.c

@@ -120,7 +120,7 @@ static int init_filters(const char *filters_descr)
     inputs->pad_idx    = 0;
     inputs->next       = NULL;
 
-    if ((ret = avfilter_graph_parse(filter_graph, filter_descr,
+    if ((ret = avfilter_graph_parse(filter_graph, filters_descr,
                                     &inputs, &outputs, NULL)) < 0)
         return ret;