layers: Rename PV device extension enables

Change-Id: I4078b279dd812694c358fdcc9f23f5620befaca0
diff --git a/layers/parameter_validation_utils.h b/layers/parameter_validation_utils.h
index 0f4bdb6..45140a9 100644
--- a/layers/parameter_validation_utils.h
+++ b/layers/parameter_validation_utils.h
@@ -61,7 +61,7 @@
     VkPhysicalDeviceFeatures physical_device_features = {};
     VkPhysicalDevice physical_device = VK_NULL_HANDLE;
     VkDevice device = VK_NULL_HANDLE;
-    DeviceExtensions enables;
+    DeviceExtensions extensions;
     std::unordered_set<std::string> enabled_extensions;
 
     VkLayerDispatchTable dispatch_table = {};