[IA64-SGI] io_init.c: gcc4 fixes for sn2

This patch is needed since "warning: use of cast expressions as lvalues is
deprecated" turned into an error in gcc4.  We can use the convenience macros
for read access and explicit assignments for initialization.  I thought about
using Alexandre's fixes, but this seemed a little simpler.
Signed-off-by: Jesse Barnes <jbarnes@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

arch/ia64/sn/kernel/io_init.c

@@ -202,7 +202,7 @@ static void sn_pci_fixup_slot(struct pci_dev *dev)
 	struct pci_dev *host_pci_dev;
 	int status = 0;
 
-	SN_PCIDEV_INFO(dev) = kmalloc(sizeof(struct pcidev_info), GFP_KERNEL);
+	dev->sysdata = kmalloc(sizeof(struct pcidev_info), GFP_KERNEL);
 	if (SN_PCIDEV_INFO(dev) <= 0)
 		BUG();		/* Cannot afford to run out of memory */
 	memset(SN_PCIDEV_INFO(dev), 0, sizeof(struct pcidev_info));
@@ -310,8 +310,8 @@ static void sn_pci_controller_fixup(int segment, int busnum)
 	 * after this point.
 	 */
 
-	PCI_CONTROLLER(bus) = controller;
-	SN_PCIBUS_BUSSOFT(bus) = provider_soft;
+	bus->sysdata = controller;
+	PCI_CONTROLLER(bus)->platform_data = provider_soft;
 
 	nasid = NASID_GET(SN_PCIBUS_BUSSOFT(bus)->bs_base);
 	cnode = nasid_to_cnodeid(nasid);