Do not create log table handler if run in bootstrap mode.

This patch also fixes annoying complains on the log tables
absence, issued by the shell version of mysql-test-run.


sql/log.h:
  check for the table log handler presence, as now it
  could be absent in some cases. Namely, during bootstrap.
sql/mysqld.cc:
  do not create log table handler, if run
  in bootstrap mode.

sql/log.h

@@ -473,11 +473,17 @@ public:
   bool flush_logs(THD *thd);
   THD *get_general_log_thd()
   {
+    if (table_log_handler)
       return (THD *) table_log_handler->general_log_thd;
+    else
+      return NULL;
   }
   THD *get_slow_log_thd()
   {
+    if (table_log_handler)
       return (THD *) table_log_handler->slow_log_thd;
+    else
+      return NULL;
   }
   /* Perform basic logger cleanup. this will leave e.g. error log open. */
   void cleanup_base();

sql/mysqld.cc

@@ -3086,6 +3086,9 @@ static int init_server_components()
   }
 
 #ifdef WITH_CSV_STORAGE_ENGINE
+  if (opt_bootstrap)
+    opt_old_log_format= TRUE;
+  else
     logger.init_log_tables();
 
   if (opt_old_log_format || (have_csv_db != SHOW_OPTION_YES))