misc cleanups for nvme-pci

[Keith Busch]

On Tue, May 13, 2025 at 09:00:16AM +0200, Christoph Hellwig wrote:
> this has misc cleanups for the nvme-pci I/O code.  Most of this was done
> as part of the new DMA API work.  Which then clashed with the per-node
> dmapools, so I'll try to get it out now instead of having to do another
> rebase.  As part of that this also includes minor tidyups for the new code
> from the per-node dmapools.

Series looks good. Just a minor optimization suggestion from me for
patch 5, and commit log issue Kanchan mentioned for patch 2.

Reviewed-by: Keith Busch <kbusch at kernel.org>