remove nvme_reinit_tagset and blk_mq_tagset_iter

Christoph Hellwig
2018-06-14T12:30:13Z

Now that nvme-fc moved off the reinit request concept both the core nvme
and blk-mq code for it becomes unused.

Jens, are you ok with queuing up the blk-mq side with the pending nvme
changes?