alinux: pci/iohub-sriov: fix iohub-sriov VF probe issue

fix #26111716

When doing VF probing, it will fail when calling pci_enable_sriov()
function, as we should only call this function for physfn. Fix this
issue by adding physfn check before the call.

Fixes: 4a5d2b59 ("alinux: pci/iohub-sriov: Support for Alibaba PCIe IOHub SRIOV")
Signed-off-by: Nshanghui.lsh <shanghui.lsh@alibaba-inc.com>
Reviewed-by: Nluanshi <zhangliguang@linux.alibaba.com>
[ caspar: modify the commit log]
Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>

drivers/pci/iohub-sriov/iohub-sriov.c

@@ -56,11 +56,13 @@ xdragon_sriov_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 	}
 
 	/* VF number fixed as 255, will change to a parameter later */
-	err = pci_enable_sriov(dev, 255);
-	if (err) {
-		dev_err(&dev->dev, "Failed to enable PCI sriov: %d\n",
-			err);
-		goto error;
+	if (dev->is_physfn) {
+		err = pci_enable_sriov(dev, 255);
+		if (err) {
+			dev_err(&dev->dev, "Failed to enable PCI sriov: %d\n",
+					err);
+			goto error;
+		}
 	}
 
 	return 0;