Return after XDCHECK when avgObjSize=0 so debug env can fail

Summary: move check and return for avgobjSize = 0 after XDCHECK to let debug fail

Reviewed By: byahn0996

Differential Revision: D73970656

fbshipit-source-id: 70b6aacdb9ce7e0e3bca240eeb13eb88183fb5ca

Author: pbhandar2

cachelib/object_cache/ObjectCacheSizeController.h

@@ -140,10 +140,10 @@ void ObjectCacheSizeController<AllocatorT>::work() {
   // First thing, we want to take care of is to make sure that the total
   // object size and number of objects are within the limit.
   auto averageObjSize = totalObjSize / currentNumEntries;
+  XDCHECK_NE(0u, averageObjSize);
   if (averageObjSize == 0) {
     return;
   }
-  XDCHECK_NE(0u, averageObjSize);
   auto newEntriesLimit =
       objCache_.config_.totalObjectSizeLimit / averageObjSize;