fix comment typo (#5721)
fix comment typo (#5721)


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