virtio/vhost: assign the virtio/vhost_drvier to device->priv before probe

So the driver can get the driver pointer by vdev/hdev->priv,
and later vdev/hdev->priv can be used to store other data such as the
virtio/vhost drivers' private data.

Signed-off-by: Bowen Wang <wangbowen6@xiaomi.com>

drivers/vhost/vhost.c

@@ -130,16 +130,16 @@ static void vhost_defered_probe_work(FAR void *arg)
         {
           if (item->device->id.device == driver->device)
             {
+              item->device->priv = driver;
               if (driver->probe(item->device) >= 0)
                 {
                   vhosterr("device probe success device=%p\n", item->device);
                   item->driver = driver;
-                }
-
                   break;
                 }
             }
         }
+    }
 
   if (!list_is_empty(&g_vhost_bus.defered_device))
     {
@@ -207,6 +207,7 @@ int vhost_register_driver(FAR struct vhost_driver *driver)
            * matched.
            */
 
+          item->device->priv = driver;
           if (driver->probe(item->device) >= 0)
             {
               item->driver = driver;

drivers/virtio/virtio.c

@@ -225,13 +225,14 @@ int virtio_register_driver(FAR struct virtio_driver *driver)
       FAR struct virtio_device_item_s *item =
         container_of(node, struct virtio_device_item_s, node);
       FAR struct virtio_device *device = item->device;
-      if (driver->device == device->id.device)
+      if (item->driver == NULL && driver->device == device->id.device)
         {
           /* If found the device in the device list, call driver probe,
            * if probe success, assign item->driver to indicate the device
            * matched.
            */
 
+          device->priv = driver;
           if (driver->probe(device) >= 0)
             {
               item->driver = driver;
@@ -327,14 +328,14 @@ int virtio_register_device(FAR struct virtio_device *device)
            * matched.
            */
 
+          device->priv = driver;
           if (driver->probe(device) >= 0)
             {
               item->driver = driver;
-            }
-
               break;
             }
         }
+    }
 
   nxmutex_unlock(&g_virtio_bus.lock);
   return ret;