scsi: core: Do not increase scsi_device's iorequest_cnt if dispatch failed

If scsi_dispatch_cmd() failed, the SCSI command was not sent to the target.
scsi_queue_rq() would return BLK_STS_RESOURCE if scsi_dispatch_cmd()
failed, and the related request would be requeued. The timeout of this
request would not fire, so noone would increase iodone_cnt.
Signed-off-by: Wenchao Hao <haowenchao@huawei.com>
Link: https://lore.kernel.org/r/20221123122137.150776-3-haowenchao@huawei.comReviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/scsi_lib.c

@@ -1464,8 +1464,6 @@ static int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
 	struct Scsi_Host *host = cmd->device->host;
 	int rtn = 0;
 
-	atomic_inc(&cmd->device->iorequest_cnt);
-
 	/* check if the device is still usable */
 	if (unlikely(cmd->device->sdev_state == SDEV_DEL)) {
 		/* in SDEV_DEL we error all commands. DID_NO_CONNECT
@@ -1764,6 +1762,7 @@ static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx,
 		goto out_dec_host_busy;
 	}
 
+	atomic_inc(&cmd->device->iorequest_cnt);
 	return BLK_STS_OK;
 
 out_dec_host_busy: