Update use of Quantity in other classes

contrib/mesos/pkg/scheduler/resources/resource.go

@@ -85,14 +85,8 @@ func podResources(pod *api.Pod, resourceName api.ResourceName, def, min resource
 		}
 
 		// add up the request and limit sum for all containers
-		err = requestSum.Add(request)
-		if err != nil {
-			return
-		}
-		err = limitSum.Add(limit)
-		if err != nil {
-			return
-		}
+		requestSum.Add(request)
+		limitSum.Add(limit)
 
 		// optionally write request and limit back
 		if write {