qbus_new(), called in i2c_init_bus(), should not be called
on unrealized device.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-id: 20231020130331.50048-10-philmd@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>