face: remove pointless method UdpFace::handleFirstReceive

Simply call DatagramFace::receiveDatagram directly.

Change-Id: Icec976fb9f4a008d08ece56c28ac652ea615bc76
diff --git a/daemon/face/multicast-udp-face.cpp b/daemon/face/multicast-udp-face.cpp
index c3d7e95..a69b1c2 100644
--- a/daemon/face/multicast-udp-face.cpp
+++ b/daemon/face/multicast-udp-face.cpp
@@ -55,8 +55,7 @@
 {
   m_sendSocket->async_send_to(boost::asio::buffer(block.wire(), block.size()),
                               m_multicastGroup,
-                              bind(&DatagramFace<protocol, Multicast>::handleSend,
-                                   this, _1, block));
+                              bind(&MulticastUdpFace::handleSend, this, _1, block));
 }
 
 void