block/blk-rq-qos: delete useless enmu RQ_QOS_IOPRIO

Since blk-ioprio handing was converted from a rqos policy to a direct call,
RQ_QOS_IOPRIO is not used anymore, just delete it.

Signed-off-by: Li Jinlin <lijinlin3@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20220916023241.32926-1-lijinlin3@huawei.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-mq-debugfs.c

@@ -805,8 +805,6 @@ static const char *rq_qos_id_to_name(enum rq_qos_id id)
 		return "latency";
 	case RQ_QOS_COST:
 		return "cost";
-	case RQ_QOS_IOPRIO:
-		return "ioprio";
 	}
 	return "unknown";
 }

block/blk-rq-qos.h

@@ -17,7 +17,6 @@ enum rq_qos_id {
 	RQ_QOS_WBT,
 	RQ_QOS_LATENCY,
 	RQ_QOS_COST,
-	RQ_QOS_IOPRIO,
 };
 
 struct rq_wait {