nvme/host: Use the enum req_op and blk_opf_t types

Improve static type checking by using the enum req_op type for variables
that represent a request operation and the new blk_opf_t type for
variables that represent request flags.

Reviewed-by: Sagi Grimberg <[e-mail]>
Cc: Christoph Hellwig <[e-mail]>
Cc: Keith Busch <[e-mail]>
Signed-off-by: Bart Van Assche <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jens Axboe <[e-mail]>

drivers/nvme/host/ioctl.c

···
 		struct nvme_command *cmd, void __user *ubuffer,
 		unsigned bufflen, void __user *meta_buffer, unsigned meta_len,
 		u32 meta_seed, void **metap, unsigned timeout, bool vec,
-		unsigned int rq_flags, blk_mq_req_flags_t blk_flags)
+		blk_opf_t rq_flags, blk_mq_req_flags_t blk_flags)
 {
 	bool write = nvme_is_write(cmd);
 	struct nvme_ns *ns = q->queuedata;
···
 	struct nvme_uring_data d;
 	struct nvme_command c;
 	struct request *req;
-	unsigned int rq_flags = 0;
+	blk_opf_t rq_flags = 0;
 	blk_mq_req_flags_t blk_flags = 0;
 	void *meta = NULL;
 

drivers/nvme/host/nvme.h

···
 int nvme_wait_freeze_timeout(struct nvme_ctrl *ctrl, long timeout);
 void nvme_start_freeze(struct nvme_ctrl *ctrl);
 
-static inline unsigned int nvme_req_op(struct nvme_command *cmd)
+static inline enum req_op nvme_req_op(struct nvme_command *cmd)
 {
 	return nvme_is_write(cmd) ? REQ_OP_DRV_OUT : REQ_OP_DRV_IN;
 }