v5.9-rc1 commit reliably breaks pci nvme detection

[Christoph Hellwig]

On Thu, Aug 20, 2020 at 11:10:58AM -0600, Jens Axboe wrote:
> To be fair, I've only heard this one complaint about it, so hopefully it's
> not too widespread. I'm on an x86-64 laptop myself with nvme, and it works
> just fine :-)

The cause for this is the weird NVMe of by ones, where 0 in a field
means 1.  So for the overflow to happen you need a controller that
supports USHORT_MAX queue entries.  Which don't seem to be all that
common.