[PATCH 1/2] nvme-pci: allocate nvme_command within driver pdu

[Christoph Hellwig]

On Tue, Mar 16, 2021 at 10:06:31AM -0700, Keith Busch wrote:
> All the nvme transport drivers had allocated the nvme command within the
> driver's pdu except for pci. Align pci with everyone else and replace
> the stack variable with the pdu command.

At some point in this series nvme_request.cmd should become the
actual structure instead of a pointer so that we can remove this
indiretion.  I'd be tempted to just do this in the initial patch,
but I'm fine with any kind of patch ordering.