Revert "usb: release the created buses"

The USB device don't hold the bus. There is no ASAN related reports
anymore.

This reverts commit cd7bc87868.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-id: 20180613172815.32738-3-marcandre.lureau@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

hw/usb/dev-storage.c

@@ -588,13 +588,6 @@ static const struct SCSIBusInfo usb_msd_scsi_info_bot = {
     .load_request = usb_msd_load_request,
 };
 
-static void usb_msd_unrealize_storage(USBDevice *dev, Error **errp)
-{
-    MSDState *s = USB_STORAGE_DEV(dev);
-
-    object_unref(OBJECT(&s->bus));
-}
-
 static void usb_msd_storage_realize(USBDevice *dev, Error **errp)
 {
     MSDState *s = USB_STORAGE_DEV(dev);
@@ -642,13 +635,6 @@ static void usb_msd_storage_realize(USBDevice *dev, Error **errp)
     s->scsi_dev = scsi_dev;
 }
 
-static void usb_msd_bot_unrealize(USBDevice *dev, Error **errp)
-{
-    MSDState *s = USB_STORAGE_DEV(dev);
-
-    object_unref(OBJECT(&s->bus));
-}
-
 static void usb_msd_bot_realize(USBDevice *dev, Error **errp)
 {
     MSDState *s = USB_STORAGE_DEV(dev);
@@ -712,7 +698,6 @@ static void usb_msd_class_storage_initfn(ObjectClass *klass, void *data)
     USBDeviceClass *uc = USB_DEVICE_CLASS(klass);
 
     uc->realize = usb_msd_storage_realize;
-    uc->unrealize = usb_msd_unrealize_storage;
     dc->props = msd_properties;
 }
 
@@ -775,7 +760,6 @@ static void usb_msd_class_bot_initfn(ObjectClass *klass, void *data)
     USBDeviceClass *uc = USB_DEVICE_CLASS(klass);
 
     uc->realize = usb_msd_bot_realize;
-    uc->unrealize = usb_msd_bot_unrealize;
     uc->attached_settable = true;
 }
 

hw/usb/dev-uas.c

@@ -896,8 +896,6 @@ static void usb_uas_unrealize(USBDevice *dev, Error **errp)
     UASDevice *uas = USB_UAS(dev);
 
     qemu_bh_delete(uas->status_bh);
-
-    object_unref(OBJECT(&uas->bus));
 }
 
 static void usb_uas_realize(USBDevice *dev, Error **errp)