Fix results after Bug#12661768 fix.

mysql-test/suite/innodb_plugin/r/innodb.result

@@ -1313,7 +1313,7 @@ FOREIGN KEY (c1) REFERENCES t1 (c1) ON UPDATE CASCADE
 INSERT INTO t1 VALUES ('old', 'somevalu'), ('other', 'anyvalue');
 INSERT INTO t2 VALUES (10, 'old'), (20, 'other');
 UPDATE t1 SET c1 = 'other' WHERE c1 = 'old';
-ERROR 23000: Upholding foreign key constraints for table 't1', entry '', key 2 would lead to a duplicate entry
+ERROR 23000: Upholding foreign key constraints for table 't1', entry 'other-somevalu', key 2 would lead to a duplicate entry
 DROP TABLE t2,t1;
 create table t1(
 id int primary key,