tests: fix modules-test with no default machine

Fixes: eb062cfa733 ("tests: add module loading test")
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-id: 20190827140241.20818-2-marcandre.lureau@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

tests/modules-test.c

@@ -1,12 +1,14 @@
 #include "qemu/osdep.h"
 #include "libqtest.h"
 
+const char common_args[] = "-nodefaults -machine none";
+
 static void test_modules_load(const void *data)
 {
     QTestState *qts;
     const char **args = (const char **)data;
 
-    qts = qtest_init(NULL);
+    qts = qtest_init(common_args);
     qtest_module_load(qts, args[0], args[1]);
     qtest_quit(qts);
 }