MDEV-15020 fixup: Make trx_t::apply_log() truly ATTRIBUTE_COLD

storage/innobase/trx/trx0trx.cc

@@ -1429,7 +1429,8 @@ TRANSACTIONAL_TARGET void trx_t::commit_low(mtr_t *mtr)
 
   if (mtr)
   {
-    apply_log();
+    if (UNIV_UNLIKELY(apply_online_log))
+      apply_log();
     trx_write_serialisation_history(this, mtr);
 
     /* The following call commits the mini-transaction, making the

storage/innobase/trx/trx0undo.cc

@@ -360,10 +360,8 @@ inline void UndorecApplier::apply_undo_rec()
 /** Apply any changes to tables for which online DDL is in progress. */
 ATTRIBUTE_COLD void trx_t::apply_log()
 {
-  if (undo_no == 0 || apply_online_log == false)
-    return;
   const trx_undo_t *undo= rsegs.m_redo.undo;
-  if (!undo)
+  if (!undo || !undo_no)
     return;
   page_id_t page_id{rsegs.m_redo.rseg->space->id, undo->hdr_page_no};
   page_id_t next_page_id(page_id);