[CBRD-21560] Syntax errors can occur when a view containing TRUNC() or ROUND() function is fetched

[hgryoo]

http://jira.cubrid.org/browse/CBRD-21560

This change removes the returning error block when "default" is specified in fmt argument for TRUNC() and ROUND().

create table foo (a int, b date);
insert into foo values (1, '20170821');
insert into foo values (2, NULL);

create view foo_num as select trunc(sysdate-b) c1, round(sysdate-b) c2 from foo;
select * from foo_num;

create view foo_dt as select trunc(sysdate) c1, round(sysdate) c2 from foo;
select * from foo_dt;

The following is query specification information of each view.

csql> ;schema foo_num
...
 <VClass Name> 
     foo_num
...
 <Query_specifications> 
     select  trunc( SYS_DATE -[foo].[b], _iso88591'default'),  round( SYS_DATE -[foo].[b], _iso88591'default') from [foo] [foo]

csql> ;schema foo_dt
...
 <VClass Name> 
     foo_dt
...
<Query_specifications> 
     select  trunc([foo].[b], _iso88591'default'),  round([foo].[b], _iso88591'default') from [foo] [foo]

For both cases, "check syntax at 'default'" error occurred before the change.

csql> select * from foo_num;

=== <Result of SELECT Command in Line 1> ===

                    c1                    c2
============================================
                  1109                  1109
                  NULL                  NULL

csql> select * from foo_dt;

=== <Result of SELECT Command in Line 1> ===

  c1          c2        
========================
  09/03/2020  09/03/2020
  09/03/2020  09/03/2020