Fix mysqldump.test to work with non-standard --vardir.

(Backported from mysql-5.1-new)

mysql-test/t/mysqldump.test

@@ -1050,14 +1050,14 @@ create algorithm=merge view v4 as select * from t1 with cascaded check option;
 create algorithm =temptable view v5 as select * from t1;
 
 # dump tables and views
---exec $MYSQL_DUMP test > var/tmp/bug14871.sql
+--exec $MYSQL_DUMP test > $MYSQLTEST_VARDIR/tmp/bug14871.sql
 
 # drop the db, tables and views
 drop table t1;
 drop view v1, v2, v3, v4, v5;
 
 # Reload dump
---exec $MYSQL test < var/tmp/bug14871.sql
+--exec $MYSQL test < $MYSQLTEST_VARDIR/tmp/bug14871.sql
 
 # check that all tables and views could be created
 show tables;
@@ -1083,13 +1083,13 @@ end|
 delimiter ;|
 
 # dump table and trigger
---exec $MYSQL_DUMP test > var/tmp/bug16878.sql
+--exec $MYSQL_DUMP test > $MYSQLTEST_VARDIR/tmp/bug16878.sql
 drop trigger tr1;
 drop trigger tr2;
 drop table t1, t2;
 
 # reload dump
---exec $MYSQL test < var/tmp/bug16878.sql
+--exec $MYSQL test < $MYSQLTEST_VARDIR/tmp/bug16878.sql
 --replace_column 6 #
 show triggers;
 drop trigger tr1;