Remove unnecessary branch.

PiperOrigin-RevId: 551006963

src/google/protobuf/metadata_lite.h

@@ -182,12 +182,11 @@ class PROTOBUF_EXPORT InternalMetadata {
 
   template <typename T>
   PROTOBUF_NOINLINE void DeleteOutOfLineHelper() {
-    // TODO(b/188560391): Determine if this branch is needed.
-    if (!arena()) {
     delete PtrValue<Container<T>>();
+    // TODO(b/188560391):  This store is load-bearing.  Since we are destructing
+    // the message at this point, see if we can eliminate it.
     ptr_ = 0;
   }
-  }
 
   template <typename T>
   PROTOBUF_NOINLINE T* mutable_unknown_fields_slow() {