[PATCH v2 2/2] nvme: use blk_mq_[un]quiesce_tagset

[Christoph Hellwig]

> Something like this:

That definitively seems like a sensible prep patch.

In the long run NVME_CTRL_STOPPED probably needs to be integrated
with the controller state machine, and moving it from the ns to
the ctrl is a good step towards that.