fixed race when calculating DC offsets and start times due to ec_slave_config_attach: removed obsolete request to change slave state to OP.

The request to change to OP is done by ec_master_request_op after activating the master.

master/slave_config.c

@@ -244,8 +244,6 @@ int ec_slave_config_attach(
     slave->config = sc;
     sc->slave = slave;
 
-    ec_slave_request_state(slave, EC_SLAVE_STATE_OP);
-
     EC_CONFIG_DBG(sc, 1, "Attached slave %u.\n", slave->ring_position);
 
     return 0;