L4 brief ok

StgSharp.Common/HighPerformance/Memory/L4.Prefetch.cs

@@ -82,6 +82,7 @@ namespace StgSharp.HighPerformance.Memory
                 CacheLineHead* head = (CacheLineHead*)handle;
                 int index = head->_id;
                 (*_eviction)[index] = 0; // reset eviction counter
+                return true;
             }
             return false;
         }