tests: New helper qtest_qmp_receive_success()

Commit b21373d0713 copied wait_command() from tests/migration-test.c
to tests/tpm-util.c.  Replace both copies by new libqtest helper
qtest_qmp_receive_success().  Also use it to simplify
qtest_qmp_device_del().

Bonus: gets rid of a non-literal format string.  A step towards
compile-time format string checking without triggering
-Wformat-nonliteral.

Cc: Thomas Huth <thuth@redhat.com>
Cc: Juan Quintela <quintela@redhat.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Stefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180806065344.7103-17-armbru@redhat.com>

1 files changed, 9 insertions, 20 deletions

diff --git a/tests/migration-test.c b/tests/migration-test.c
index db652e30a0..402c82bdc4 100644
--- a/tests/migration-test.c
+++ b/tests/migration-test.c
@@ -149,31 +149,20 @@ static void wait_for_serial(const char *side)
     } while (true);
 }
 
+static void stop_cb(void *opaque, const char *name, QDict *data)
+{
+    if (!strcmp(name, "STOP")) {
+        got_stop = true;
+    }
+}
+
 /*
  * Events can get in the way of responses we are actually waiting for.
  */
 static QDict *wait_command(QTestState *who, const char *command)
 {
-    const char *event_string;
-    QDict *response, *ret;
-
-    response = qtest_qmp(who, command);
-
-    while (qdict_haskey(response, "event")) {
-        /* OK, it was an event */
-        event_string = qdict_get_str(response, "event");
-        if (!strcmp(event_string, "STOP")) {
-            got_stop = true;
-        }
-        qobject_unref(response);
-        response = qtest_qmp_receive(who);
-    }
-
-    ret = qdict_get_qdict(response, "return");
-    g_assert(ret);
-    qobject_ref(ret);
-    qobject_unref(response);
-    return ret;
+    qtest_qmp_send(who, command);
+    return qtest_qmp_receive_success(who, stop_cb, NULL);
 }
 
 /*