small fix to flowid

Change-Id: I7ba950cf3fe874a094ddd3f93a8d72df0cba89c0
diff --git a/core/api/src/main/java/org/onlab/onos/net/flow/FlowId.java b/core/api/src/main/java/org/onlab/onos/net/flow/FlowId.java
index c7c44cb..6bcf1db 100644
--- a/core/api/src/main/java/org/onlab/onos/net/flow/FlowId.java
+++ b/core/api/src/main/java/org/onlab/onos/net/flow/FlowId.java
@@ -13,7 +13,7 @@
         this.flowid = id;
     }
 
-    public static FlowId valueOf(int id) {
+    public static FlowId valueOf(long id) {
         return new FlowId(id);
     }