of: address: Fix documented return value of of_pci_range_to_resource()

of_pci_range_to_resource() returns a negative instead of a positive
error code.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/bcdaa9332e9c6dfa27af68d79fda121eac2975dc.1680248888.git.geert+renesas@glider.beSigned-off-by: Rob Herring <robh@kernel.org>

drivers/of/address.c

@@ -213,7 +213,7 @@ EXPORT_SYMBOL_GPL(of_pci_address_to_resource);
  * @res:	pointer to a valid resource that will be updated to
  *              reflect the values contained in the range.
  *
- * Returns EINVAL if the range cannot be converted to resource.
+ * Returns -EINVAL if the range cannot be converted to resource.
  *
  * Note that if the range is an IO range, the resource will be converted
  * using pci_address_to_pio() which can fail if it is called too early or