hwcontext: Perform usual uninitialisation on derived frames contexts

libavutil/hwcontext.c

@@ -205,10 +205,6 @@ static void hwframe_ctx_free(void *opaque, uint8_t *data)
 {
     AVHWFramesContext *ctx = (AVHWFramesContext*)data;
 
-    if (ctx->internal->source_frames) {
-        av_buffer_unref(&ctx->internal->source_frames);
-
-    } else {
     if (ctx->internal->pool_internal)
         av_buffer_pool_uninit(&ctx->internal->pool_internal);
 
@@ -217,7 +213,8 @@ static void hwframe_ctx_free(void *opaque, uint8_t *data)
 
     if (ctx->free)
         ctx->free(ctx);
-    }
+
+    av_buffer_unref(&ctx->internal->source_frames);
 
     av_buffer_unref(&ctx->device_ref);