chain-dma: fix scheduling exception

Task state shouldn't be modified by client code, it is fully managed
by the scheduler. Setting task status to INIT after scheduling a task
is wrong and for chain DMA it leads to a scheduler exception. Simply
remove the offending line.

BugLink: thesofproject#7084
Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>

Author: lyakh

src/audio/chain_dma.c

@@ -303,7 +303,6 @@ static int chain_task_start(struct comp_dev *dev)
 	}
 
 	pm_policy_state_lock_get(PM_STATE_RUNTIME_IDLE, PM_ALL_SUBSTATES);
-	cd->chain_task.state = SOF_TASK_STATE_INIT;
 	k_spin_unlock(&drivers->lock, key);
 
 	return 0;