Avoid use of Objects.hash when there's only 1 params

- directly call #hashCode() when hashed Object seems non-null
- replace with Objects.hashCode(Object) when Nullable
- replace with Long.hashCode(long), etc. when primitive

Change-Id: I08c24ebbe94cf4162d1491209a14baf953163e41
diff --git a/incubator/api/src/main/java/org/onosproject/incubator/net/domain/DomainEdge.java b/incubator/api/src/main/java/org/onosproject/incubator/net/domain/DomainEdge.java
index 4a42a74..ad5e5d1 100644
--- a/incubator/api/src/main/java/org/onosproject/incubator/net/domain/DomainEdge.java
+++ b/incubator/api/src/main/java/org/onosproject/incubator/net/domain/DomainEdge.java
@@ -39,7 +39,7 @@
 
     @Override
     public int hashCode() {
-        return 43 * super.hashCode() + Objects.hash(connectPoint);
+        return 43 * super.hashCode() + connectPoint.hashCode();
     }
 
     @Override