Fix small memory leak that occured when BerkeleyDB failed to initialize.

  {

    db_env->close(db_env,0); /* purecov: inspected */

    db_env=0; /* purecov: inspected */

    goto err;

  }

  (void) hash_init(&bdb_open_tables,system_charset_info,32,0,0,

		   (hash_get_key) bdb_get_key,0,0);

  pthread_mutex_init(&bdb_mutex,MY_MUTEX_INIT_FAST);

err:

  DBUG_RETURN(db_env == 0);

}