Sequence queue error callbacks with queue destroy.

HSA v1.2 update.

Change-Id: I13975e71b2c1ea5b7738236f5d02df84312ad00c

runtime/hsa-runtime/core/runtime/runtime.cpp

@@ -1222,6 +1222,9 @@ void Runtime::Unload() {
   amd::hsa::loader::Loader::Destroy(loader_);
   loader_ = nullptr;
 
+  std::for_each(gpu_agents_.begin(), gpu_agents_.end(), DeleteObject());
+  gpu_agents_.clear();
+
   async_events_control_.Shutdown();
 
   if (vm_fault_signal_ != nullptr) {