scsi: megaraid: Use pci_dev_id() to simplify the code

PCI core API pci_dev_id() can be used to get the BDF number for a PCI
device. We don't need to compose it manually. Use pci_dev_id() to simplify
the code a little bit.
Signed-off-by: Jialin Zhang <zhangjialin11@huawei.com>
Link: https://lore.kernel.org/r/20230815025419.3523236-4-zhangjialin11@huawei.comSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/megaraid/megaraid_mbox.c

@@ -438,7 +438,7 @@ megaraid_probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
 
 
 	// set up PCI related soft state and other pre-known parameters
-	adapter->unique_id	= pdev->bus->number << 8 | pdev->devfn;
+	adapter->unique_id	= pci_dev_id(pdev);
 	adapter->irq		= pdev->irq;
 	adapter->pdev		= pdev;