missing element in prelocked_mode_name[] array

different fix for a63a250d:

BUG#23509275 :DBUG_PRINT in THD::decide_logging_format prints incorrectly, access out-of-bound

sql/sql_class.cc

@@ -4736,9 +4736,11 @@ int THD::decide_logging_format(TABLE_LIST *tables)
     {
       static const char *prelocked_mode_name[] = {
         "NON_PRELOCKED",
+        "LOCK_TABLES",
         "PRELOCKED",
         "PRELOCKED_UNDER_LOCK_TABLES",
       };
+      compile_time_assert(array_elements(prelocked_mode_name) == LTM_always_last);
       DBUG_PRINT("debug", ("prelocked_mode: %s",
                            prelocked_mode_name[locked_tables_mode]));
     }

sql/sql_class.h

@@ -1075,7 +1075,8 @@ enum enum_locked_tables_mode
   LTM_NONE= 0,
   LTM_LOCK_TABLES,
   LTM_PRELOCKED,
-  LTM_PRELOCKED_UNDER_LOCK_TABLES
+  LTM_PRELOCKED_UNDER_LOCK_TABLES,
+  LTM_always_last
 };