g_usb_device_bulk_transfer_finish: Use g_simple_async_result_is_valid
g_usb_device_bulk_transfer_finish: Use g_simple_async_result_is_valid

nacho/libgusb,hughsie/libgusb,nacho/libgusb,hughsie/libgusb,robert-ancell/libgusb,robert-ancell/libgusb,hughsie/libgusb