PCI: Don't try to restore VF BARs

VF BARs are read-only zero, so updating VF BARs will not have any effect.
See the SR-IOV spec r1.1, sec 3.4.1.11.

Don't update VF BARs in pci_restore_bars().

This avoids spurious "BAR %d: error updating" messages that we see when
doing vfio pass-through after 6eb7018705de ("vfio-pci: Move idle devices to
D3hot power state").

[bhelgaas: changelog, fix whitespace]
Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
index 232f925..152de5c 100644
--- a/drivers/pci/setup-res.c
+++ b/drivers/pci/setup-res.c
@@ -36,6 +36,11 @@
 	enum pci_bar_type type;
 	struct resource *res = dev->resource + resno;
 
+	if (dev->is_virtfn) {
+		dev_warn(&dev->dev, "can't update VF BAR%d\n", resno);
+		return;
+	}
+
 	/*
 	 * Ignore resources for unimplemented BARs and unused resource slots
 	 * for 64 bit BARs.