PCI: Drop error data fabrication when config read fails

If config pci_ops.read() methods return failure, the PCI_OP_READ() and
PCI_USER_READ_CONFIG() wrappers use PCI_SET_ERROR_RESPONSE() to set the
data value, so there's no need to set it in the pci_ops.read() methods
themselves.

Drop the unnecessary data value fabrication when pci_ops.read() fails.

Link: https://lore.kernel.org/r/1b2edb060cf19b45f70645b331e6c08c9ba798c0.1637243717.git.naveennaidu479@gmail.comSigned-off-by: Naveen Naidu <naveennaidu479@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rob Herring <robh@kernel.org>

drivers/pci/access.c

@@ -83,10 +83,8 @@ int pci_generic_config_read(struct pci_bus *bus, unsigned int devfn,
 	void __iomem *addr;
 
 	addr = bus->ops->map_bus(bus, devfn, where);
-	if (!addr) {
-		*val = ~0;
+	if (!addr)
 		return PCIBIOS_DEVICE_NOT_FOUND;
-	}
 
 	if (size == 1)
 		*val = readb(addr);
@@ -125,10 +123,8 @@ int pci_generic_config_read32(struct pci_bus *bus, unsigned int devfn,
 	void __iomem *addr;
 
 	addr = bus->ops->map_bus(bus, devfn, where & ~0x3);
-	if (!addr) {
-		*val = ~0;
+	if (!addr)
 		return PCIBIOS_DEVICE_NOT_FOUND;
-	}
 
 	*val = readl(addr);