add missing test result

followup for 21bcfeb9

storage/rocksdb/mysql-test/rocksdb/r/mariadb_port_fixes.result

@@ -96,3 +96,14 @@ CREATE TABLE t1 (a INT) ENGINE=RocksDB;
 INSERT INTO t1 VALUES (1);
 ALTER TABLE t1 AUTO_INCREMENT 10;
 DROP TABLE t1;
+# 
+# MDEV-16155: UPDATE on RocksDB table with unique constraint does not work
+# 
+CREATE TABLE t1 (a INT, b CHAR(8), UNIQUE INDEX(a)) ENGINE=RocksDB;
+INSERT INTO t1 (a,b) VALUES (1,'foo'),(2,'bar');
+UPDATE t1 SET a=a+100;
+SELECT * FROM t1;
+a	b
+101	foo
+102	bar
+DROP TABLE t1;