nvme: delete dev from dev_list in nvme_reset

Device resets need to delete the device from the device list before
kicking of the reset an re-probe, otherwise we get the device added
to the list twice.  nvme_reset is the only side missing this deletion
at the moment, and this patch adds it.

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