layers: Fix vkGetPipelineCacheSize validation.
diff --git a/layers/param_checker.cpp b/layers/param_checker.cpp
index fd9b56f..38f1ca8 100644
--- a/layers/param_checker.cpp
+++ b/layers/param_checker.cpp
@@ -4683,9 +4683,11 @@
     VkDevice device,
     VkPipelineCache pipelineCache)
 {
-    get_dispatch_table(pc_device_table_map, device)->GetPipelineCacheSize(device, pipelineCache);
+    size_t result = get_dispatch_table(pc_device_table_map, device)->GetPipelineCacheSize(device, pipelineCache);
 
     PostGetPipelineCacheSize(device, pipelineCache);
+
+    return result;
 }
 
 bool PostGetPipelineCacheData(