!656 【OpenHarmony开源贡献者计划2022】fix: warning of unused variable 'lastValue'

Merge pull request !656 from rtos_shang/master

frameworks/components/ui_slider.cpp

@@ -368,7 +368,9 @@ bool UISlider::OnRotateEvent(const RotateEvent& event)
         return UIView::OnRotateEvent(event);
     }
     cachedRotation_ = 0;
+#if ENABLE_VIBRATOR
     int32_t lastValue = curValue_;
+#endif
     SetValue(curValue_ + realRotation);
     if (listener_ != nullptr) {
         listener_->OnChange(curValue_);