usb-bus: convert USBDeviceClass init to realize

Add "realize/unrealize" in USBDeviceClass, which has errp
as a parameter. So all the implementations now use
error_setg instead of error_report for reporting error.

Note: this patch still keep "init" in USBDeviceClass, and
call kclass->init in usb_device_realize(), avoid breaking
git bisect. After realize all usb devices, will be removed.

Signed-off-by: Gonglei <arei.gonglei@huawei.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
diff --git a/include/hw/usb.h b/include/hw/usb.h
index 6b32a3b..612f09f 100644
--- a/include/hw/usb.h
+++ b/include/hw/usb.h
@@ -267,11 +267,17 @@
 #define USB_DEVICE_GET_CLASS(obj) \
      OBJECT_GET_CLASS(USBDeviceClass, (obj), TYPE_USB_DEVICE)
 
+typedef void (*USBDeviceRealize)(USBDevice *dev, Error **errp);
+typedef void (*USBDeviceUnrealize)(USBDevice *dev, Error **errp);
+
 typedef struct USBDeviceClass {
     DeviceClass parent_class;
 
     int (*init)(USBDevice *dev);
 
+    USBDeviceRealize realize;
+    USBDeviceUnrealize unrealize;
+
     /*
      * Walk (enabled) downstream ports, check for a matching device.
      * Only hubs implement this.
@@ -544,9 +550,9 @@
                            void *opaque, USBPortOps *ops, int speedmask);
 void usb_port_location(USBPort *downstream, USBPort *upstream, int portnr);
 void usb_unregister_port(USBBus *bus, USBPort *port);
-int usb_claim_port(USBDevice *dev);
+void usb_claim_port(USBDevice *dev, Error **errp);
 void usb_release_port(USBDevice *dev);
-int usb_device_attach(USBDevice *dev);
+void usb_device_attach(USBDevice *dev, Error **errp);
 int usb_device_detach(USBDevice *dev);
 int usb_device_delete_addr(int busnr, int addr);