For the NVMe device given, sends a Vendor Unique WDC Purge command and
provides the result.
The <device> parameter is mandatory and may be either the NVMe character
device (ex: /dev/nvme0), or a namespace block device (ex: /dev/nvme0n1).
This will only work on WDC devices supporting this feature.
Results for any other device are undefined.
On success it returns 0, error code otherwise.