avfilter/af_superequalizer: stop leaking s->out frame

Signed-off-by: Paul B Mahol <onemda@gmail.com>

libavfilter/af_superequalizer.c

@@ -302,6 +302,7 @@ static av_cold void uninit(AVFilterContext *ctx)
 {
     SuperEqualizerContext *s = ctx->priv;
 
+    av_frame_free(&s->out);
     av_freep(&s->irest);
     av_freep(&s->ires);
     av_freep(&s->fsamples);