Bug #46827 rpl_circular_for_4_hosts failed on PB2

This test case tests a circular replication of four hosts. 
A--->B--->C--->D--->A
The replicate is slow and needs more time to replicate all data in the circle.
The time it spends to replicate, sometimes, is longer than the time that 
wait_condition.inc spends to wait that all data has been replicated. This
cause sporadical failure of this test case.
  
This patch uses sync_slave_with_master to ensure that all data can be replicated
successfully in the circle.

mysql-test/suite/rpl/t/rpl_circular_for_4_hosts.test

@@ -233,16 +233,7 @@ COMMIT;
 --connection master_a
 --enable_query_log
 
-
---let $wait_condition= SELECT COUNT(*)=400 FROM t2 WHERE c = 1
---connection master_a
---source include/wait_condition.inc
---connection master_b
---source include/wait_condition.inc
---connection master_c
---source include/wait_condition.inc
---connection master_d
---source include/wait_condition.inc
+--source include/circular_rpl_for_4_hosts_sync.inc
 
 --connection master_a
 SELECT 'Master A',b,COUNT(*) FROM t2 WHERE c = 1 GROUP BY b ORDER BY b;
@@ -282,15 +273,7 @@ ROLLBACK;
 --connection master_a
 --enable_query_log
 
---let $wait_condition= SELECT COUNT(*)=200 FROM t2 WHERE c = 2
---connection master_a
---source include/wait_condition.inc
---connection master_b
---source include/wait_condition.inc
---connection master_c
---source include/wait_condition.inc
---connection master_d
---source include/wait_condition.inc
+--source include/circular_rpl_for_4_hosts_sync.inc
 
 --connection master_a
 SELECT 'Master A',b,COUNT(*) FROM t2 WHERE c = 2 GROUP BY b ORDER BY b;