Fixes for failures in test scripts and removal of some compiler warnings

- rpl_gtid_stop_start:  Random failure
- sysvars_innodb,32bit: Fixes for 32 bit

Author: montywi

mysql-test/suite/rpl/r/rpl_gtid_stop_start.result

@@ -8,6 +8,7 @@ include/stop_slave.inc
 Master_Log_File = 'master-bin.000001'
 Using_Gtid = 'No'
 CHANGE MASTER TO master_use_gtid=current_pos;
+FLUSH LOGS;
 connection server_1;
 FLUSH LOGS;
 include/wait_for_purge.inc "master-bin.000002"

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

@@ -28,6 +28,7 @@ CHANGE MASTER TO master_use_gtid=current_pos;
 --write_file $MYSQLTEST_VARDIR/tmp/mysqld.2.expect
 wait
 EOF
+FLUSH LOGS;
 --shutdown_server 30
 --source include/wait_until_disconnected.inc