cleanup: reduce code duplication

Author: vuvova

sql/sql_base.cc

@@ -4739,6 +4739,9 @@ prepare_fk_prelocking_list(THD *thd, Query_tables_list *prelocking_ctx,
   Query_arena *arena, backup;
   TABLE *table= table_list->table;
 
+  if (!table->file->referenced_by_foreign_key())
+    DBUG_RETURN(FALSE);
+
   arena= thd->activate_stmt_arena_if_needed(&backup);
 
   table->file->get_parent_foreign_key_list(thd, &fk_list);
@@ -4824,16 +4827,12 @@ bool DML_prelocking_strategy::handle_table(THD *thd,
         return TRUE;
     }
 
-    if (table->file->referenced_by_foreign_key())
-    {
-      if (prepare_fk_prelocking_list(thd, prelocking_ctx, table_list,
-                                     need_prelocking,
-                                     table_list->trg_event_map))
-        return TRUE;
-    }
+    if (prepare_fk_prelocking_list(thd, prelocking_ctx, table_list,
+                                   need_prelocking,
+                                   table_list->trg_event_map))
+      return TRUE;
   }
-  else if (table_list->slave_fk_event_map &&
-           table->file->referenced_by_foreign_key())
+  else if (table_list->slave_fk_event_map)
   {
     if (prepare_fk_prelocking_list(thd, prelocking_ctx, table_list,
                                    need_prelocking,