tests: add oob-test for qapi-schema

It simply tests the new OOB capability, and make sure the QAPISchema can
parse it correctly.

Signed-off-by: Peter Xu <peterx@redhat.com>
Message-Id: <20180326063901.27425-7-peterx@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
diff --git a/tests/test-qmp-cmds.c b/tests/test-qmp-cmds.c
index 93fbbb1..db690cc 100644
--- a/tests/test-qmp-cmds.c
+++ b/tests/test-qmp-cmds.c
@@ -16,6 +16,10 @@
 {
 }
 
+void qmp_an_oob_command(Error **errp)
+{
+}
+
 Empty2 *qmp_user_def_cmd0(Error **errp)
 {
     return g_new0(Empty2, 1);