Fix the return value of jerry_to_property_descriptor function (#4371)

JerryScript-DCO-1.0-Signed-off-by: Zoltan Herczeg zherczeg.u-szeged@partner.samsung.com

docs/02.API-REFERENCE.md

@@ -4071,12 +4071,13 @@ This API function is equivalent to ToPropertyDescriptor operation defined in ECM
 It decodes the ECMAScript object and fills the fields of a JerryScript property descriptor.
 
 *Notes*:
-- The es.next profile enables this by default.
+- Returned value must be freed with [jerry_release_value](#jerry_release_value) when it
+  is no longer needed.
 
 **Prototype**
 
 ```c
-bool
+jerry_value_t
 jerry_to_property_descriptor (jerry_value_t obj_value, jerry_property_descriptor_t *out_prop_desc_p);
 ```
 
@@ -4084,8 +4085,10 @@ jerry_to_property_descriptor (jerry_value_t obj_value, jerry_property_descriptor
 - `src_prop_desc_p` - the output property descriptor.
 - return
   - [jerry_value_t](#jerry_value_t)
-  - true - if success
-  - false - if error occurs
+  - true, if success
+  - thrown error, otherwise
+
+*New in version [[NEXT_RELEASE]]*.
 
 **Example**
 
@@ -4102,9 +4105,9 @@ example (void)
   jerry_value_t value = jerry_create_boolean (true);
   jerry_property_descriptor_t prop_desc;
 
-  jerry_set_property (object, prop_name, prop_name);
+  jerry_release_value (jerry_set_property (object, prop_name, prop_name));
 
-  jerry_to_property_descriptor (object, &prop_desc);
+  jerry_release_value (jerry_to_property_descriptor (object, &prop_desc));
 
   jerry_release_value (object);
   jerry_release_value (prop_name);