block: change ->make_request_fn() and users to return a queue cookie

No functional changes in this patch, but it prepares us for returning
a more useful cookie related to the IO that was queued up.

Signed-off-by: Jens Axboe <axboe@fb.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>
diff --git a/include/linux/lightnvm.h b/include/linux/lightnvm.h
index 5ebd70d..69c9057 100644
--- a/include/linux/lightnvm.h
+++ b/include/linux/lightnvm.h
@@ -426,7 +426,7 @@
 	return ppa;
 }
 
-typedef void (nvm_tgt_make_rq_fn)(struct request_queue *, struct bio *);
+typedef blk_qc_t (nvm_tgt_make_rq_fn)(struct request_queue *, struct bio *);
 typedef sector_t (nvm_tgt_capacity_fn)(void *);
 typedef int (nvm_tgt_end_io_fn)(struct nvm_rq *, int);
 typedef void *(nvm_tgt_init_fn)(struct nvm_dev *, struct gendisk *, int, int);