qapi job: 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/job.json.

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

Cc: John Snow <jsnow@redhat.com>
Cc: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Cc: qemu-block@nongnu.org
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-Id: <20221104160712.3005652-15-armbru@redhat.com>

job-qmp.c

@@ -156,8 +156,7 @@ static JobInfo *job_query_single_locked(Job *job, Error **errp)
         .status             = job->status,
         .current_progress   = progress_current,
         .total_progress     = progress_total,
-        .has_error          = !!job->err,
-        .error              = job->err ? \
+        .error              = job->err ?
                               g_strdup(error_get_pretty(job->err)) : NULL,
     };
 

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/job.json',
             'qapi/machine.json',
             'qapi/machine-target.json',
             'qapi/migration.json',