Similarly to commit e63ed64c ("tests/qtest/virtio-net-failover:
Use g_file_open_tmp() to create temporary file"), avoid calling
g_test_rand_int() before g_test_init(): use g_file_open_tmp().

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20211224234504.3413370-1-philmd@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>