PCI: Fix return value from pci_user_{read,write}_config_*()

The PCI user-space config accessors pci_user_{read,write}_config_*() return
negative error numbers, which were introduced by commit 34e3207205ef
("PCI: handle positive error codes").  That patch converted all positive
error numbers from platform-specific PCI config accessors to -EINVAL, which
means the callers don't know anything about the specific cause of the
failure.

The patch fixes the issue by converting the positive PCIBIOS_* error values
to generic negative error numbers with pcibios_err_to_errno().

[bhelgaas: changelog]
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Greg Thelen <gthelen@google.com>
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 018877b..322335a 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -518,7 +518,7 @@
 	case PCIBIOS_FUNC_NOT_SUPPORTED:
 		return -ENOENT;
 	case PCIBIOS_BAD_VENDOR_ID:
-		return -EINVAL;
+		return -ENOTTY;
 	case PCIBIOS_DEVICE_NOT_FOUND:
 		return -ENODEV;
 	case PCIBIOS_BAD_REGISTER_NUMBER:
@@ -529,7 +529,7 @@
 		return -ENOSPC;
 	}
 
-	return -ENOTTY;
+	return -ERANGE;
 }
 
 /* Low-level architecture-dependent routines */