Fix missing return statement in MPLS label allocation

Change-Id: I1ff26d253585d09b75ceecf819efa0d027057e50
diff --git a/core/net/src/main/java/org/onosproject/net/intent/impl/compiler/PathCompiler.java b/core/net/src/main/java/org/onosproject/net/intent/impl/compiler/PathCompiler.java
index 50114ec..9425164 100644
--- a/core/net/src/main/java/org/onosproject/net/intent/impl/compiler/PathCompiler.java
+++ b/core/net/src/main/java/org/onosproject/net/intent/impl/compiler/PathCompiler.java
@@ -264,7 +264,7 @@
         List<ResourceAllocation> allocations =
                 creator.resourceService().allocate(intent.id(), ImmutableList.copyOf(resources));
         if (allocations.isEmpty()) {
-            Collections.emptyMap();
+            return Collections.emptyMap();
         }
 
         return labels;