executor: fix scope ambiguity of joinResult (#23876)
executor: fix scope ambiguity of joinResult (#23876)

 
pingcap/tidb,ngaut/tidb,pingcap/tidb,c4pt0r/tidb,kyle-wang/tidb,ngaut/tidb,ngaut/tidb,c4pt0r/tidb,pingcap/tidb,coocood/tidb,kyle-wang/tidb,kyle-wang/tidb,kyle-wang/tidb,c4pt0r/tidb,ngaut/tidb,pingcap/tidb,pingcap/tidb,c4pt0r/tidb,ngaut/tidb,pingcap/tidb,c4pt0r/tidb,coocood/tidb,kyle-wang/tidb,kyle-wang/tidb,c4pt0r/tidb,ngaut/tidb