adjust to vmod_priv methods

Ref:
https://github.com/varnishcache/varnish-cache/commit/681c11998ec56dc4460a30585210f95a7850ea3b

src/vmod_hoailona.c

@@ -525,7 +525,7 @@ vmod_hosts_policy(VRT_CTX, struct vmod_hoailona_hosts *hosts,
 		}
 		task->magic = VMOD_HOAILONA_POLICY_TASK_MAGIC;
 		priv_task->priv = task;
-		priv_task->free = NULL;
+		AZ(priv_task->methods);
 	}
 	else {
 		WS_Contains(ctx->ws, priv_task->priv,