node device: Fix locking issue in virNodeDeviceDestroy

Certain error paths won't unlock the node device object.

src/node_device/node_device_driver.c

@@ -720,6 +720,8 @@ nodeDeviceDestroy(virNodeDevicePtr dev)
     }
 
 out:
+    if (obj)
+        virNodeDeviceObjUnlock(obj);
     VIR_FREE(parent_name);
     VIR_FREE(wwnn);
     VIR_FREE(wwpn);