querry operation finished state in loop which could be more efficient

offloading-cacher/cache.hpp

@@ -695,6 +695,7 @@ inline void dsacache::CacheData::WaitOnCompletion() {
     bool error = false;
 
     for (auto& handler : *local_handlers) {
+        while (!handler.is_finished()) sched_yield();
         auto result = handler.get();
 
         if (result.status != dml::status_code::ok) {