Fixed packet request for multiple devices

Currently, it only installs the reuqest to the first registered device.

Change-Id: Ie376760be26544a9f8ece98d76e962cf536ca7cb
diff --git a/core/store/dist/src/main/java/org/onosproject/store/packet/impl/DistributedPacketStore.java b/core/store/dist/src/main/java/org/onosproject/store/packet/impl/DistributedPacketStore.java
index 25429ad..c2f713a 100644
--- a/core/store/dist/src/main/java/org/onosproject/store/packet/impl/DistributedPacketStore.java
+++ b/core/store/dist/src/main/java/org/onosproject/store/packet/impl/DistributedPacketStore.java
@@ -221,6 +221,7 @@
                     firstRequest.set(true);
                     return ImmutableSet.of(request);
                 } else if (!existingRequests.contains(request)) {
+                    firstRequest.set(true);
                     return ImmutableSet.<PacketRequest>builder()
                                        .addAll(existingRequests)
                                        .add(request)