nvme-pci: fix missed admin queue sq doorbell write

We can batch admin commands submitted through io_uring_cmd passthrough,
which means bd->last may be false and skips the doorbell write to
aggregate multiple commands per write. If a subsequent command can't be
dispatched for whatever reason, we have to provide the blk-mq ops'
commit_rqs callback in order to ensure we properly update the doorbell.

Fixes: 58e5bdeb9c2b ("nvme: enable uring-passthrough for admin commands")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>