qdev: use a wrapper to access reset and promote reset to a class method

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
diff --git a/hw/qdev.c b/hw/qdev.c
index 5da94a8..a80ca7c 100644
--- a/hw/qdev.c
+++ b/hw/qdev.c
@@ -48,7 +48,12 @@
 static void qdev_subclass_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
+
     dc->info = data;
+    dc->reset = dc->info->reset;
+
+    /* Poison to try to detect future uses */
+    dc->info->reset = NULL;
 }
 
 DeviceInfo *qdev_get_info(DeviceState *dev)
@@ -378,8 +383,8 @@
                                        dev->alias_required_for_version);
     }
     dev->state = DEV_STATE_INITIALIZED;
-    if (dev->hotplugged && qdev_get_info(dev)->reset) {
-        qdev_get_info(dev)->reset(dev);
+    if (dev->hotplugged) {
+        device_reset(dev);
     }
     return 0;
 }
@@ -407,9 +412,7 @@
 
 static int qdev_reset_one(DeviceState *dev, void *opaque)
 {
-    if (qdev_get_info(dev)->reset) {
-        qdev_get_info(dev)->reset(dev);
-    }
+    device_reset(dev);
 
     return 0;
 }
@@ -1593,6 +1596,15 @@
     qdev_get_peripheral();
 }
 
+void device_reset(DeviceState *dev)
+{
+    DeviceClass *klass = DEVICE_GET_CLASS(dev);
+
+    if (klass->reset) {
+        klass->reset(dev);
+    }
+}
+
 static TypeInfo device_type_info = {
     .name = TYPE_DEVICE,
     .parent = TYPE_OBJECT,