Flip before returning ByteBuffer

Change-Id: I7350e24f20d5686a8c6c43291d963070fe7da792
diff --git a/src/main/java/net/onrc/onos/ofcontroller/networkgraph/LinkEvent.java b/src/main/java/net/onrc/onos/ofcontroller/networkgraph/LinkEvent.java
index 4d060de..5fd3b82 100644
--- a/src/main/java/net/onrc/onos/ofcontroller/networkgraph/LinkEvent.java
+++ b/src/main/java/net/onrc/onos/ofcontroller/networkgraph/LinkEvent.java
@@ -52,9 +52,9 @@
 
     public static ByteBuffer getLinkID(Long src_dpid, Long src_port_no,
 	    Long dst_dpid, Long dst_port_no) {
-	return ByteBuffer.allocate(LinkEvent.LINKID_BYTES).putChar('L')
+	return (ByteBuffer) ByteBuffer.allocate(LinkEvent.LINKID_BYTES).putChar('L')
 		.put(PortEvent.getPortID(src_dpid, src_port_no))
-		.put(PortEvent.getPortID(dst_dpid, dst_port_no));
+		.put(PortEvent.getPortID(dst_dpid, dst_port_no)).flip();
     }
 
     public byte[] getID() {