lightnvm: cleanup queue before target removal

This prevents outstanding IOs to be sent for completion to target after
the target has been removed. The flow is now: stop new IOs > cleanup
queue > remove target.

Signed-off-by: Javier Gonzalez <[e-mail]>
Signed-off-by: Matias Bjørling <[e-mail]>
Signed-off-by: Jens Axboe <[e-mail]>

drivers/lightnvm/core.c

···
 	lockdep_assert_held(&nvm_lock);
 
 	del_gendisk(tdisk);
+	blk_cleanup_queue(q);
+
 	if (tt->exit)
 		tt->exit(tdisk->private_data);
-
-	blk_cleanup_queue(q);
 
 	put_disk(tdisk);