Revert "Rename the differencing disk to avoid conflict with parent disk."
Revert "Rename the differencing disk to avoid conflict with parent disk."

This reverts commit f46aa781771a833bc9feaa9296667145d1082eb3.

HuijingHei/lis-test,chvalean/lis-test,bogdancarpusor/lis-test,LIS/lis-test,LIS/lis-test,ilenghel/lis-test,bogdancarpusor/lis-test,chvalean/lis-test,lixuemin2016/lis-test,bogdancarpusor/lis-test,HuijingHei/lis-test,lixuemin2016/lis-test,LIS/lis-test,ilenghel/lis-test,ilenghel/lis-test,LIS/lis-test,mihaico/lis-test,lixuemin2016/lis-test,ampintilie/lis-test,adriansuhov/lis-test,chvalean/lis-test,chvalean/lis-test,HuijingHei/lis-test,mihaico/lis-test,senugala/lis-test,mihaico/lis-test,ilenghel/lis-test,ampintilie/lis-test,adriansuhov/lis-test,ampintilie/lis-test,HuijingHei/lis-test,senugala/lis-test,adriansuhov/lis-test,ampintilie/lis-test,adriansuhov/lis-test,senugala/lis-test,lixuemin2016/lis-test