Replace pci_read_config_word() with pcie_capability_read_word().
pcie_capability_read_word() takes care of a few special cases when reading
the PCIe capability. See 8c0d3a02c1 ("PCI: Add accessors for PCI Express
Capability").
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>