PCI: ibmphp: Remove unneeded NULL test

Remove unneeded NULL test.  The index variable of list_for_each_entry is
never NULL, as it is the structure that contains the list pointer.

Generated by: scripts/coccinelle/iterators/itnull.cocci

Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: Geliang Tang <geliangtang@163.com>