fix comment and tiny optimisation for shutdown.
fix comment and tiny optimisation for shutdown.

Change-Id: I94e0f55f7fc38529a9ab165786efaf7ac649a9d3

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core