fixed a wrong directory in distinct.test

mysql-test/t/distinct.test

@@ -491,12 +491,12 @@ SELECT DISTINCT fruit_id, fruit_name INTO OUTFILE
 '../tmp/data1.tmp' FROM t1 WHERE fruit_name = 'APPLE';
 LOAD DATA INFILE '../tmp/data1.tmp' INTO TABLE t2;
 --error 0,1
---remove_file $MYSQL_TEST_DIR/var/tmp/data1.tmp
+--remove_file $MYSQLTEST_VARDIR/tmp/data1.tmp
 
 SELECT DISTINCT @v19:= fruit_id, @v20:= fruit_name INTO OUTFILE 
 '../tmp/data2.tmp' FROM t1 WHERE fruit_name = 'APPLE';
 LOAD DATA INFILE '../tmp/data2.tmp' INTO TABLE t2;
---remove_file $MYSQL_TEST_DIR/var/tmp/data2.tmp
+--remove_file $MYSQLTEST_VARDIR/tmp/data2.tmp
 
 SELECT @v19, @v20;
 SELECT * FROM t2;