linux-phytec-ti

nvme: remove dead controllers from a work item

Compared to the kthread this gives us multiple call prevention for free.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>