nvme-pci: shutdown on timeout during deletion

We do not restart a controller in a deleting state for timeout errors.
When in this state, unblock potential request dispatchers with failed
completions by shutting down the controller on timeout detection.

Reported-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>