delete PADDLE_WITH_TESTING in memory_block_desc (#41817)

* delete PADDLE_WITH_TESTING in memory_block_desc

* test FLAGS_allocator_strategy=naive_best_fit

* delete flag naive_best_fit

paddle/fluid/memory/detail/memory_block_desc.cc

@@ -62,18 +62,12 @@ inline size_t hash(const MemoryBlock::Desc& metadata, size_t initial_seed) {
 }  // namespace
 
 void MemoryBlock::Desc::UpdateGuards() {
-#ifdef PADDLE_WITH_TESTING
   guard_begin = hash(*this, 1);
   guard_end = hash(*this, 2);
-#endif
 }
 
 bool MemoryBlock::Desc::CheckGuards() const {
-#ifdef PADDLE_WITH_TESTING
   return guard_begin == hash(*this, 1) && guard_end == hash(*this, 2);
-#else
-  return true;
-#endif
 }
 
 }  // namespace detail