[PATCH] Add a parameter for NVME_IOCTL_ID to get Namespaces ID

[Zouming (IT)]

> This break any existing user.  I also don't really understand the
> problem you're trying to solve..
> 
> .
> 
The problem trying to solve is below:
1、According to nvme spec, the possible range of Namespaces ID is form 1 to FFFFFFFe
2、When use NVME_IOCTL_ID IOCTL cmd to get namespaces ID，if return error before function nvme_ioctl，
How can user distinguish the return value is valid namespaces ID or error value。

Do you think this situation exsits or there will never fail when use NVME_IOCTL_ID cmd?