DevReattacher: Use aggregate init for Callback<>

smocore/deviceManager/deviceReattacher.cpp

@@ -72,8 +72,7 @@ void DeviceReattacher::onTimeout(const boost::system::error_code& error)
 
 	// Attempt to reattach all unattached devices from the known list
 	parent.attachAllUnattachedDevicesFromKnownListReq(
-		Callback<DeviceManager::attachAllUnattachedDevicesFromReqCbFn>(
-			nullptr, reattachmentCb));
+		{ nullptr, reattachmentCb});
 
 	// Schedule the next timeout
 	scheduleNextTimeout();