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.