scsi: qla2xxx: Fix inconsistent format argument type in qla_dbg.c

Fix the following warning:

[drivers/scsi/qla2xxx/qla_dbg.c:2451]: (warning) %ld in format string (no. 4)
	requires 'long' but the argument type is 'unsigned long'.

Link: https://lore.kernel.org/r/20200930022515.2862532-4-yebin10@huawei.com
Reported-by: Hulk Robot <hulkci@huawei.com>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Reviewed-by: Nilesh Javali <njavali@marvell.com>
Signed-off-by: Ye Bin <yebin10@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/qla2xxx/qla_dbg.c

@@ -2449,7 +2449,7 @@ static void ql_dbg_prefix(char *pbuf, int pbuf_size,
 		const struct pci_dev *pdev = vha->hw->pdev;
 
 		/* <module-name> [<dev-name>]-<msg-id>:<host>: */
-		snprintf(pbuf, pbuf_size, "%s [%s]-%04x:%ld: ", QL_MSGHDR,
+		snprintf(pbuf, pbuf_size, "%s [%s]-%04x:%lu: ", QL_MSGHDR,
 			 dev_name(&(pdev->dev)), msg_id, vha->host_no);
 	} else {
 		/* <module-name> [<dev-name>]-<msg-id>: : */