virt: vbox: convert to use dev_groups

The driver core supports the ability to handle the creation and removal
of device-specific sysfs files in a race-free manner. Moreover, it can
guarantee the success of creation. Therefore, it should be better to
convert to use dev_groups.

Fixes: 0ba002bc

 ("virt: Add vboxguest driver for Virtual Box Guest integration")
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Link: https://lore.kernel.org/r/20220901144610.3550300-1-jiasheng@iscas.ac.cn


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>