uacce: fix cdev handling in the cleanup path

In the Linux kernel, the following vulnerability has been resolved:

uacce: fix cdev handling in the cleanup path

When cdev_device_add fails, it internally releases the cdev memory, and if cdev_device_del is then executed, it will cause a hang error. To fix it, we check the return value of cdev_device_add() and clear uacce->cdev to avoid calling cdev_device_del in the uacce_remove.