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.be


Signed-off-by: Rob Herring <robh@kernel.org>