ONOS-5531: Port Label bug

Change-Id: I14e3b1c16de54b229f6823ffa199743d7a5308e8
diff --git a/web/gui/src/main/webapp/app/view/topo/topoLink.js b/web/gui/src/main/webapp/app/view/topo/topoLink.js
index ca2982c..bfe0df5 100644
--- a/web/gui/src/main/webapp/app/view/topo/topoLink.js
+++ b/web/gui/src/main/webapp/app/view/topo/topoLink.js
@@ -195,9 +195,9 @@
         var offset = 32,
             pos = link.position,
             nearX = src ? pos.x1 : pos.x2,
-            nearY = src ? pos.y2 : pos.y1,
+            nearY = src ? pos.y1 : pos.y2,
             farX = src ? pos.x2 : pos.x1,
-            farY = src ? pos.y1 : pos.y2;
+            farY = src ? pos.y2 : pos.y1;
 
         function dist(x, y) { return Math.sqrt(x*x + y*y); }