[#6599] Make description a little bit more clear

Author: wouterj

reference/forms/types/entity.rst

@@ -205,10 +205,8 @@ Allows you to create a custom query for your choices. See
 The value of this option can either be a ``QueryBuilder`` object, a Closure or
 ``null`` (which will load all entities). When using a Closure, you will be
 passed the ``EntityRepository`` of the entity as the only argument and should
-return a ``QueryBuilder``.
-
-If you'd like to use default loading of all entries, you can return ``null`` in
-the Closure as well.
+return a ``QueryBuilder``. Returning ``null`` in the Closure will result in
+loading all entities.
 
 .. versionadded:: 2.8
     Returning ``null`` in the Closure was introduced in Symfony 2.8.