Initialize padding for core message queues

Change-Id: Iebf79869216a6f2e24b307e3c9b2273887fb3864
diff --git a/applications/message_handler/lib/include/message_queue.hpp b/applications/message_handler/lib/include/message_queue.hpp
index 4140c62..ec9d7b6 100644
--- a/applications/message_handler/lib/include/message_queue.hpp
+++ b/applications/message_handler/lib/include/message_queue.hpp
@@ -29,7 +29,7 @@
     EthosU::ethosu_core_queue_header header;
     uint8_t data[SIZE];
 
-    constexpr Queue() : header({SIZE, 0, 0}) {}
+    constexpr Queue() : header({SIZE, 0, {0}, 0}) {}
 
     constexpr EthosU::ethosu_core_queue *toQueue() {
         return reinterpret_cast<EthosU::ethosu_core_queue *>(&header);