qapi: Drop qapi_event_send_FOO()'s Error ** argument

The generated qapi_event_send_FOO() take an Error ** argument.  They
can't actually fail, because all they do with the argument is passing it
to functions that can't fail: the QObject output visitor, and the
@qmp_emit callback, which is either monitor_qapi_event_queue() or
event_test_emit().

Drop the argument, and pass &error_abort to the QObject output visitor
and @qmp_emit instead.

Suggested-by: Eric Blake <eblake@redhat.com>
Suggested-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20180815133747.25032-4-peterx@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Commit message rewritten, update to qapi-code-gen.txt corrected]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
diff --git a/tests/test-qmp-event.c b/tests/test-qmp-event.c
index 8677094..9cddd72 100644
--- a/tests/test-qmp-event.c
+++ b/tests/test-qmp-event.c
@@ -95,7 +95,7 @@
 
 /* This function is hooked as final emit function, which can verify the
    correctness. */
-static void event_test_emit(test_QAPIEvent event, QDict *d, Error **errp)
+static void event_test_emit(test_QAPIEvent event, QDict *d)
 {
     QDict *t;
     int64_t s, ms;
@@ -156,7 +156,7 @@
     QDict *d;
     d = data->expect;
     qdict_put_str(d, "event", "EVENT_A");
-    qapi_event_send_event_a(&error_abort);
+    qapi_event_send_event_a();
 }
 
 static void test_event_b(TestEventData *data,
@@ -165,7 +165,7 @@
     QDict *d;
     d = data->expect;
     qdict_put_str(d, "event", "EVENT_B");
-    qapi_event_send_event_b(&error_abort);
+    qapi_event_send_event_b();
 }
 
 static void test_event_c(TestEventData *data,
@@ -191,7 +191,7 @@
     qdict_put_str(d, "event", "EVENT_C");
     qdict_put(d, "data", d_data);
 
-    qapi_event_send_event_c(true, 1, true, &b, "test2", &error_abort);
+    qapi_event_send_event_c(true, 1, true, &b, "test2");
 
     g_free(b.string);
 }
@@ -233,8 +233,7 @@
     qdict_put_str(d, "event", "EVENT_D");
     qdict_put(d, "data", d_data);
 
-    qapi_event_send_event_d(&a, "test3", false, NULL, true, ENUM_ONE_VALUE3,
-                           &error_abort);
+    qapi_event_send_event_d(&a, "test3", false, NULL, true, ENUM_ONE_VALUE3);
 
     g_free(struct1.string);
     g_free(a.string);