Simplify ConnectPoint#toString format

for ease of reading logs.

Change-Id: I981cf877eb53f64e77fdef48bca30625942bc8f2

@@ -15,8 +15,6 @@
  */
 package org.onosproject.net;
 
-import com.google.common.base.MoreObjects;
-
 import java.util.Objects;
 
 import static com.google.common.base.Preconditions.checkArgument;
@@ -166,10 +164,7 @@ public class ConnectPoint {
 
     @Override
     public String toString() {
-        return MoreObjects.toStringHelper(this)
-                .add("elementId", elementId)
-                .add("portNumber", portNumber)
-                .toString();
+        return elementId + "/" + portNumber;
     }
 
 }

@@ -123,7 +123,7 @@ public class LinkKeyTest {
         LinkKey k1 = LinkKey.linkKey(SRC1, DST1);
         String k1String = k1.toString();
         assertThat(k1String, allOf(containsString("LinkKey{"),
-                                   containsString("src=ConnectPoint{elementId=1, portNumber=1}"),
-                                   containsString("dst=ConnectPoint{elementId=2, portNumber=1}")));
+                                   containsString("src=1/1"),
+                                   containsString("dst=2/1}")));
     }
 }