pci_host: Drop write-only address_space field

The address_space field of PCIHostState was only ever written, never used.
Drop it completely.
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: NAndreas Färber <afaerber@suse.de>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

hw/pci/pci_host.h

@@ -40,7 +40,6 @@ struct PCIHostState {
     MemoryRegion conf_mem;
     MemoryRegion data_mem;
     MemoryRegion mmcfg;
-    MemoryRegion *address_space;
     uint32_t config_reg;
     PCIBus *bus;
 };

hw/piix_pci.c

@@ -244,7 +244,6 @@ static PCIBus *i440fx_common_init(const char *device_name,
 
     dev = qdev_create(NULL, "i440FX-pcihost");
     s = PCI_HOST_BRIDGE(dev);
-    s->address_space = address_space_mem;
     b = pci_bus_new(dev, NULL, pci_address_space,
                     address_space_io, 0);
     s->bus = b;

hw/ppc/prep.c

@@ -567,7 +567,6 @@ static void ppc_prep_init(QEMUMachineInitArgs *args)
 
     dev = qdev_create(NULL, "raven-pcihost");
     pcihost = PCI_HOST_BRIDGE(dev);
-    pcihost->address_space = get_system_memory();
     object_property_add_child(qdev_get_machine(), "raven", OBJECT(dev), NULL);
     qdev_init_nofail(dev);
     pci_bus = (PCIBus *)qdev_get_child_bus(dev, "pci.0");