doc: Fix some issues with JSON_TABLE() exampls

1. Remove an unused PASSING variable.

 2. Adjust formatting of JSON data used in an example to be valid
    under strict mode

Reported-by: Miłosz Chmura <mieszko4@gmail.com>
Author: Robert Treat <rob@xzilla.net>
Discussion: https://postgr.es/m/173859550337.1071.4748984213168572913@wrigleys.postgresql.org

doc/src/sgml/func.sgml

@@ -19308,7 +19308,7 @@ SELECT jt.* FROM
 SELECT jt.* FROM
  my_films,
  JSON_TABLE (js, '$.favorites[*] ? (@.films[*].director == $filter)'
-   PASSING 'Alfred Hitchcock' AS filter, 'Vertigo' AS filter2
+   PASSING 'Alfred Hitchcock' AS filter
      COLUMNS (
      id FOR ORDINALITY,
      kind text PATH '$.kind',
@@ -19395,13 +19395,13 @@ SELECT jt.* FROM
 <programlisting>
 SELECT * FROM JSON_TABLE (
 '{"favorites":
-    {"movies":
+    [{"movies":
       [{"name": "One", "director": "John Doe"},
        {"name": "Two", "director": "Don Joe"}],
      "books":
       [{"name": "Mystery", "authors": [{"name": "Brown Dan"}]},
        {"name": "Wonder", "authors": [{"name": "Jun Murakami"}, {"name":"Craig Doe"}]}]
-}}'::json, '$.favorites[*]'
+}]}'::json, '$.favorites[*]'
 COLUMNS (
   user_id FOR ORDINALITY,
   NESTED '$.movies[*]'