vtc: Move vsl_catchup() down

It's more an action than housekeeping.

bin/varnishtest/vtc_varnish.c

@@ -195,16 +195,6 @@ wait_running(const struct varnish *v)
  * Varnishlog gatherer thread
  */
 
-static void
-vsl_catchup(const struct varnish *v)
-{
-	int vsl_idle;
-
-	vsl_idle = v->vsl_idle;
-	while (!vtc_error && vsl_idle == v->vsl_idle)
-		VTIM_sleep(0.1);
-}
-
 static void *
 varnishlog_thread(void *priv)
 {
@@ -1035,6 +1025,16 @@ varnish_expect(const struct varnish *v, char * const *av)
 	}
 }
 
+static void
+vsl_catchup(const struct varnish *v)
+{
+	int vsl_idle;
+
+	vsl_idle = v->vsl_idle;
+	while (!vtc_error && vsl_idle == v->vsl_idle)
+		VTIM_sleep(0.1);
+}
+
 /* SECTION: varnish varnish
  *
  * Define and interact with varnish instances.