This has been unused since 542f2dc7, and relies on deviceName, which
can no longer be relied upon (see issue #33128).

This needs to be removed now, as part of #33128, as the code can't be
updated to attempt device detection and fallback through to the Cinder
provided deviceName, as detection "fails" when the device is gone, and
if cinder has reported a deviceName that another volume has used in
relaity, then this will block forever (or until the other, unreleated,
volume has been detached)