Update error msg

Signed-off-by: JaySon-Huang <[email protected]>

Author: JaySon-Huang

tests/fullstack-test2/ddl/expression_index.test

@@ -33,10 +33,10 @@ mysql> set session tidb_isolation_read_engines='tiflash'; select * from test.t o
 +----+
 
 mysql> CREATE INDEX idx_n ON test.t ((null));
-ERROR 3761 (HY000): The used storage engine cannot index the expression 'null'
+ERROR 3761 (HY000) at line 1: The used storage engine cannot index the expression 'null'
 
 mysql> drop table if exists test.t;
 
 mysql> CREATE TABLE test.t (id int, KEY idx_name ((null)));
-ERROR 3761 (HY000): The used storage engine cannot index the expression 'null'
+ERROR 3761 (HY000) at line 1: The used storage engine cannot index the expression 'null'
 mysql> drop table if exists test.t;