Native multipath across multiple subsystem NQNs

[Christoph Hellwig]

The answer is neither.  The fact that NVMe with ANA required namespaces
to be be attached to the same subsystem is good and important.
TPE 4034 is retrograde and completely broken in this respect and should
have never been ratifier.  Please fix your storage system to export
virtual subsystems like everyone else and don't break the nice NVMe
architecture.