PCI: ibmphp: Remove unused assignments

Remove variables and assignments that are never used.

Found by Krzysztof using cppcheck, e.g.:

  $ cppcheck --enable=all --force
  unreadVariable drivers/pci/hotplug/ibmphp_res.c:1958 Variable 'bus_sec' is assigned a value that is never used.

Reported-by: Krzysztof Wilczyński <kw@linux.com>
Link: https://lore.kernel.org/r/20220313192933.434746-6-helgaas@kernel.org


Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>