usb devio: handle class_device_create() error

This patch adds missing class_device_create() error check,
and makes notifier return NOTIFY_BAD.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 file changed