Bug#47638 The rpl_killed_ddl test fails on Windows

When the $diff_statement variable for diff_master_slave.inc was
put in multiple lines, the rear part of the statement would be 
missing when being executed on Windows systems.

Fixed the problem by always putting the value for $diff_statement
in one line.

mysql-test/suite/rpl/t/rpl_killed_ddl.test:
  putting the statement for $diff_statement variable in one line.

mysql-test/suite/rpl/t/rpl_killed_ddl.test

@@ -158,8 +158,7 @@ source include/kill_query_and_diff_master_slave.inc;
 
 ######## EVENT ########
 
-let $diff_statement= SELECT event_name, event_body, execute_at
-                     FROM information_schema.events where event_name like 'e%';
+let $diff_statement= SELECT event_name, event_body, execute_at FROM information_schema.events where event_name like 'e%';
 
 send CREATE EVENT e2
   ON SCHEDULE AT CURRENT_TIMESTAMP + INTERVAL 1 DAY