remove an unused variable (#8229)
remove an unused variable (#8229)


Cofyc/tidb,pingcap/tidb,kyle-wang/tidb,c4pt0r/tidb,pingcap/tidb,c4pt0r/tidb,kyle-wang/tidb,kyle-wang/tidb,Cofyc/tidb,kyle-wang/tidb,ngaut/tidb,EvilMcJerkface/tidb,cosmtrek/tidb,ngaut/tidb,qiuyesuifeng/tidb,tiancaiamao/tidb,c4pt0r/tidb,XuHuaiyu/tidb,mccxj/tidb,pingcap/tidb,c4pt0r/tidb,ngaut/tidb,pingcap/tidb,ngaut/tidb,coocood/tidb,cosmtrek/tidb,ngaut/tidb,EvilMcJerkface/tidb,pingcap/tidb,XuHuaiyu/tidb,coocood/tidb,tiancaiamao/tidb,ming-relax/tidb,ngaut/tidb,c4pt0r/tidb,kyle-wang/tidb,c4pt0r/tidb,kyle-wang/tidb,ming-relax/tidb,pingcap/tidb,qiuyesuifeng/tidb,mccxj/tidb