Call the vcl_fini{} from the VGC's event(DISCARD).

bin/varnishd/cache/cache_vcl.c

@@ -290,8 +290,6 @@ VCL_Nuke(struct vcls *vcl)
 	ctx.method = VCL_MET_FINI;
 	ctx.handling = &hand;
 	ctx.vcl = vcl->conf;
-	(void)vcl->conf->fini_func(&ctx);
-	assert(hand == VCL_RET_OK);
 	AZ(vcl->conf->event_vcl(&ctx, VCL_EVENT_DISCARD));
 	free(vcl->conf->loaded_name);
 	(void)dlclose(vcl->dlh);

lib/libvcc/vcc_compile.c

@@ -334,6 +334,7 @@ EmitInitFini(const struct vcc *tl)
 	 */
 	Fc(tl, 0, "\nstatic int\nVGC_Discard(VRT_CTX)\n{\n\n");
 
+	Fc(tl, 0, "\t(void)VGC_function_vcl_fini(ctx);\n\n");
 	VTAILQ_FOREACH_REVERSE(p, &tl->inifin, inifinhead, list) {
 		AZ(VSB_finish(p->fin));
 		if (VSB_len(p->fin)) {