Integrate port up/down events with discovery

Change-Id: I7826f0a8fc285485fe62187319a3b33d6adf492b
diff --git a/src/main/java/net/onrc/onos/ofcontroller/networkgraph/LinkImpl.java b/src/main/java/net/onrc/onos/ofcontroller/networkgraph/LinkImpl.java
index 31461a5..c8954a9 100644
--- a/src/main/java/net/onrc/onos/ofcontroller/networkgraph/LinkImpl.java
+++ b/src/main/java/net/onrc/onos/ofcontroller/networkgraph/LinkImpl.java
@@ -32,12 +32,12 @@
 
 	protected void setToPorts() {
 		((PortImpl)srcPort).setOutgoingLink(this);
-		((PortImpl)srcPort).setIncomingLink(this);
+		((PortImpl)dstPort).setIncomingLink(this);
 	}
 
 	protected void unsetFromPorts() {
 		((PortImpl)srcPort).setOutgoingLink(null);
-		((PortImpl)srcPort).setIncomingLink(null);
+		((PortImpl)dstPort).setIncomingLink(null);
 	}
 
 	@Override