update help innobase_flush_log_at_trx_commitcan have vals 0, 1, 2 
ha_innobase.h, ha_innobase.cc:
  make innobase_flush_log_at_trx_commit a long, like other params


sql/ha_innobase.cc:
  make innobase_flush_log_at_trx_commit a long, like other params
sql/ha_innobase.h:
  make innobase_flush_log_at_trx_commit a long, like other params
sql/mysqld.cc:
  update help innobase_flush_log_at_trx_commitcan have vals 0, 1, 2