[PATCH 1/3] nvme-pci: Split __nvme_process_cq to poll and handle

[Christoph Hellwig]

I like this split, but I think the patch as-is is not easily
verifyable.  Can you break it out by splitting out one helper
at a time, e.g.

 patch 1: introduce nvme_ring_cq_doorbell
 patch 2: introduce nvme_handle_cqe
 patch 3: introduce nvme_read_cqe

Also there seems ot be no reason in the this patch to change the
__nvme_process_cq and nvme_process_cq return values.