powerpc/pci/hotplug: Don't need to remove from EEH cache twice

Since pcibios_release_device() called by pci_stop_and_remove_bus_device()
has removed the device from the EEH cache, we needn't do that again.

Cc: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>