avfilter/vf_avgblur: fix memory leaks if config_input() is called again

libavfilter/vf_avgblur.c

@@ -187,12 +187,21 @@ static void build_lut(AVFilterContext *ctx, int max)
     }
 }
 
+static av_cold void uninit(AVFilterContext *ctx)
+{
+    AverageBlurContext *s = ctx->priv;
+
+    av_freep(&s->buffer);
+}
+
 static int config_input(AVFilterLink *inlink)
 {
     AVFilterContext *ctx = inlink->dst;
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
     AverageBlurContext *s = ctx->priv;
 
+    uninit(ctx);
+
     s->depth = desc->comp[0].depth;
     s->max = 1 << s->depth;
     s->planewidth[1] = s->planewidth[2] = AV_CEIL_RSHIFT(inlink->w, desc->log2_chroma_w);
@@ -316,13 +325,6 @@ static int process_command(AVFilterContext *ctx, const char *cmd, const char *ar
     return 0;
 }
 
-static av_cold void uninit(AVFilterContext *ctx)
-{
-    AverageBlurContext *s = ctx->priv;
-
-    av_freep(&s->buffer);
-}
-
 static const AVFilterPad avgblur_inputs[] = {
     {
         .name         = "default",