small fix

esphome/components/sntp/sntp_component.cpp

@@ -68,8 +68,11 @@ void SNTPComponent::loop() {
   this->time_sync_callback_.call();
   this->has_time_ = true;
 
+#ifdef USE_ESP_IDF
+  // On ESP-IDF, time sync is permanent and update() doesn't force resync
   // Time is now synchronized, no need to check anymore
   this->mark_loop_done();
+#endif
 }
 
 }  // namespace sntp