ia64: Skip zero-length resources in PCI root bridge _CRS. This fixes

some ugly messages that used to show up on Tiger and other Intel
boxes:

        alloc 0xffffffff-0x0 from PCI mem for PCI Bus 0000:02 failed
        alloc 0xffffffff-0x0 from PCI mem for PCI Bus 0000:08 failed
        alloc 0xffffffff-0x0 from PCI mem for PCI Bus 0000:08 failed
        alloc 0xffffffff-0x0 from PCI mem for PCI Bus 0000:08 failed
        alloc 0xffff-0x0 from PCI IO for PCI Bus 0000:08 failed
        alloc 0xffffffff-0x0 from PCI mem for PCI Bus 0000:09 failed
        alloc 0xffffffff-0x0 from PCI mem for PCI Bus 0000:0f failed

arch/ia64/pci/pci.c

@@ -223,6 +223,9 @@ add_window (struct acpi_resource *res, void *data)
 
 	status = acpi_resource_to_address64(res, &addr);
 	if (ACPI_SUCCESS(status)) {
+		if (!addr.address_length)
+			return AE_OK;
+
 		if (addr.resource_type == ACPI_MEMORY_RANGE) {
 			flags = IORESOURCE_MEM;
 			root = &iomem_resource;