Don't panic in fini it init was never called

Ref: https://github.com/varnishcache/varnish-cache/issues/2297

src/vmod_hoailona.c

@@ -221,6 +221,8 @@ vmod_policy__fini(struct vmod_hoailona_policy **policyp)
 	struct vmod_hoailona_policy *policy;
 
 	policy = *policyp;
+	if (policy == NULL)
+		return;
 	*policyp = NULL;
 	CHECK_OBJ_NOTNULL(policy, VMOD_HOAILONA_POLICY_MAGIC);
 	if (policy->vcl_name != NULL)
@@ -268,6 +270,8 @@ vmod_hosts__fini(struct vmod_hoailona_hosts **hostsp)
 	struct host *host = NULL;
 
 	hosts = *hostsp;
+	if (hosts == NULL)
+		return;
 	*hostsp = NULL;
 	CHECK_OBJ_NOTNULL(hosts, VMOD_HOAILONA_HOSTS_MAGIC);
 	if (hosts->vcl_name != NULL)