qapi dump: Elide redundant has_FOO in generated C

The has_FOO for pointer-valued FOO are redundant, except for arrays.
They are also a nuisance to work with.  Recent commit "qapi: Start to
elide redundant has_FOO in generated C" provided the means to elide
them step by step.  This is the step for qapi/dump.json.

Said commit explains the transformation in more detail.  The invariant
violations mentioned there do not occur here.

Cc: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20221104160712.3005652-14-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

dump/dump.c

@@ -2044,8 +2044,8 @@ static void dump_process(DumpState *s, Error **errp)
     result = qmp_query_dump(NULL);
     /* should never fail */
     assert(result);
-    qapi_event_send_dump_completed(result, !!*errp, (*errp ?
-                                                     error_get_pretty(*errp) : NULL));
+    qapi_event_send_dump_completed(result,
+                                   *errp ? error_get_pretty(*errp) : NULL);
     qapi_free_DumpQueryResult(result);
 
     dump_cleanup(s);

scripts/qapi/schema.py

@@ -759,7 +759,6 @@ def need_has(self):
         assert self.type
         # Temporary hack to support dropping the has_FOO in reviewable chunks
         opt_out = [
-            'qapi/dump.json',
             'qapi/job.json',
             'qapi/machine.json',
             'qapi/machine-target.json',