Make test results stable

mysql-test/r/show_explain.result

@@ -798,7 +798,7 @@ pk	data
 20	data1
 set autocommit=0;
 select * from t1 where pk between 10 and 20 for update;
-# do: send_eval show explain for 3;
+# do: send_eval show explain for thr2;
 kill query $thr_default;
 ERROR 70100: Query execution was interrupted
 rollback;

mysql-test/t/show_explain.test

@@ -818,7 +818,7 @@ connection default;
 let $wait_condition= select State='Sending data' from information_schema.processlist where id=$thr2;
 let $thr_default=`select connection_id()`;
 --source include/wait_condition.inc
---echo # do: send_eval show explain for $thr2;
+--echo # do: send_eval show explain for thr2;
 --disable_query_log
 send_eval show explain for $thr2;
 --enable_query_log