blk-mq: remove ->map_queue

All drivers use the default, so provide an inline version of it.  If we
ever need other queue mapping we can add an optional method back,
although supporting will also require major changes to the queue setup
code.

This provides better code generation, and better debugability as well.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/block/blk-mq.h b/block/blk-mq.h
index 9087b11..ec774bf 100644
--- a/block/blk-mq.h
+++ b/block/blk-mq.h
@@ -52,6 +52,12 @@
 				   const struct cpumask *online_mask);
 extern int blk_mq_hw_queue_to_node(unsigned int *map, unsigned int);
 
+static inline struct blk_mq_hw_ctx *blk_mq_map_queue(struct request_queue *q,
+		int cpu)
+{
+	return q->queue_hw_ctx[q->mq_map[cpu]];
+}
+
 /*
  * sysfs helpers
  */