revert test changes from "cleaned up code for setting slave_parallel_mode"

but keep the code cleanup.
as it turns out, it didn't change the behavior, which is good :)

mysql-test/suite/sys_vars/r/slave_parallel_mode_basic.result

@@ -4,11 +4,7 @@ SELECT @@slave_parallel_mode;
 @@slave_parallel_mode
 domain
 SELECT @@m1.slave_parallel_mode;
-@@m1.slave_parallel_mode
-NULL
-Warnings:
-Warning	1617	There is no master connection 'm1'
-Warning	1617	There is no master connection 'm1'
+ERROR HY000: There is no master connection 'm1'
 CHANGE MASTER TO master_host='127.0.0.1', master_port=3310, master_user='root';
 SELECT @@``.slave_parallel_mode;
 @@``.slave_parallel_mode
@@ -18,14 +14,9 @@ SELECT @@slave_parallel_mode;
 domain
 Parallel_Mode = 'domain'
 SELECT @@m2.slave_parallel_mode;
-@@m2.slave_parallel_mode
-NULL
-Warnings:
-Warning	1617	There is no master connection 'm2'
-Warning	1617	There is no master connection 'm2'
+ERROR HY000: There is no master connection 'm2'
 SET GLOBAL m2.slave_parallel_mode = '';
-Warnings:
-Warning	1617	There is no master connection 'm2'
+ERROR HY000: There is no master connection 'm2'
 CHANGE MASTER 'm1' TO master_host='127.0.0.1', master_port=3311, master_user='root';
 SELECT @@m1.slave_parallel_mode;
 @@m1.slave_parallel_mode

mysql-test/suite/sys_vars/t/slave_parallel_mode_basic.test

@@ -6,6 +6,7 @@
 SET SESSION slave_parallel_mode= '';
 
 SELECT @@slave_parallel_mode;
+--error WARN_NO_MASTER_INFO
 SELECT @@m1.slave_parallel_mode;
 
 CHANGE MASTER TO master_host='127.0.0.1', master_port=3310, master_user='root';
@@ -14,7 +15,9 @@ SELECT @@slave_parallel_mode;
 --let $status_items= Parallel_Mode
 --source include/show_slave_status.inc
 
+--error WARN_NO_MASTER_INFO
 SELECT @@m2.slave_parallel_mode;
+--error WARN_NO_MASTER_INFO
 SET GLOBAL m2.slave_parallel_mode = '';
 
 CHANGE MASTER 'm1' TO master_host='127.0.0.1', master_port=3311, master_user='root';
@@ -30,5 +33,6 @@ SELECT @@slave_parallel_mode;
 SET default_master_connection= '';
 SELECT @@slave_parallel_mode;
 
+
 RESET SLAVE ALL;
 RESET SLAVE 'm1' ALL;