Fix #2335, callback in itemStyle
Fix #2335, callback in itemStyle

ecomfe/echarts,ecomfe/echarts,starlkj/echarts,starlkj/echarts,100star/echarts,willseeyou/echarts,benjaminbecktg/echarts,starlkj/echarts,benjaminbecktg/echarts,willseeyou/echarts,hexj/echarts,chenfwind/echarts,benjaminbecktg/echarts,willseeyou/echarts,xiayz/echarts,apache/incubator-echarts,100star/echarts,apache/incubator-echarts,hexj/echarts,xiayz/echarts,chenfwind/echarts,hexj/echarts