Bug#32443 - trigger.test produces warnings files

Wrong syntax for mysqltest commands was used in test file.

Fixed test.

mysql-test/r/trigger.result

@@ -1979,8 +1979,6 @@ a
 drop table table_25411_a;
 drop table table_25411_b;
 DROP TRIGGER IF EXISTS trg;
-Warnings:
-Note	1360	Trigger does not exist
 SHOW CREATE TRIGGER trg;
 ERROR HY000: Trigger does not exist
 End of 5.1 tests.

mysql-test/t/trigger.test

@@ -2250,9 +2250,9 @@ drop table table_25411_b;
 # Bug #31866: MySQL Server crashes on SHOW CREATE TRIGGER statement
 #
 
---disable-warnings
+--disable_warnings
 DROP TRIGGER IF EXISTS trg;
---enable-warnings
+--enable_warnings
 
 --error ER_TRG_DOES_NOT_EXIST
 SHOW CREATE TRIGGER trg;