nvme: set REQ_ALLOC_CACHE for uring-passthru request

This patch sets REQ_ALLOC_CACHE flag for uring-passthru requests.
This is a prep-patch so that normal / IRQ-driven uring-passthru
I/Os can also leverage bio-cache.
Signed-off-by: Anuj Gupta <anuj20.g@samsung.com>
Signed-off-by: Kanchan Joshi <joshi.k@samsung.com>
Link: https://lore.kernel.org/r/20230117120638.72254-2-anuj20.g@samsung.comSigned-off-by: Jens Axboe <axboe@kernel.dk>

drivers/nvme/host/ioctl.c

@@ -554,7 +554,7 @@ static int nvme_uring_cmd_io(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
 	struct nvme_uring_data d;
 	struct nvme_command c;
 	struct request *req;
-	blk_opf_t rq_flags = 0;
+	blk_opf_t rq_flags = REQ_ALLOC_CACHE;
 	blk_mq_req_flags_t blk_flags = 0;
 	void *meta = NULL;
 	int ret;
@@ -590,7 +590,7 @@ static int nvme_uring_cmd_io(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
 	d.timeout_ms = READ_ONCE(cmd->timeout_ms);
 
 	if (issue_flags & IO_URING_F_NONBLOCK) {
-		rq_flags = REQ_NOWAIT;
+		rq_flags |= REQ_NOWAIT;
 		blk_flags = BLK_MQ_REQ_NOWAIT;
 	}
 	if (issue_flags & IO_URING_F_IOPOLL)