tests/qapi-schema: Rename redefined-builtin to redefined-predefined

The previous commit changed this test to clash with a predefined enum
type, not a built-in type.  Adjust its name.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20210323094025.3569441-16-armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>

tests/qapi-schema/meson.build

@@ -152,9 +152,9 @@ schemas = [
   'pragma-returns-whitelist-crap.json',
   'qapi-schema-test.json',
   'quoted-structural-chars.json',
-  'redefined-builtin.json',
   'redefined-command.json',
   'redefined-event.json',
+  'redefined-predefined.json',
   'redefined-type.json',
   'reserved-command-q.json',
   'reserved-enum-q.json',

tests/qapi-schema/redefined-builtin.err

@@ -1,2 +0,0 @@
-redefined-builtin.json: In struct 'QType':
-redefined-builtin.json:2: enum type 'QType' is already defined

tests/qapi-schema/redefined-predefined.err

@@ -0,0 +1,2 @@
+redefined-predefined.json: In struct 'QType':
+redefined-predefined.json:2: enum type 'QType' is already defined