qcacmn: Do not mark pool id as INVALID_FLOW_ID in unmap

In flow control V2, dp_tx_flow_pool_vdev_unmap marks flow_pool_id as
INVALID_FLOW_ID. To free descriptors inside pool dp_tx_desc_pool_free
uses flow_pool_id to get hold of pool.

Change-Id: I892052055b34638a1ba876fac6bfcd2ae3b0d5b3
CRs-Fixed: 2228943

dp/wifi3.0/dp_tx_flow_control.c

@@ -259,9 +259,6 @@ static void dp_tx_flow_pool_vdev_unmap(struct dp_pdev *pdev,
 	}
 
 	vdev->pool = NULL;
-	qdf_spin_lock_bh(&pool->flow_pool_lock);
-	pool->flow_pool_id = INVALID_FLOW_ID;
-	qdf_spin_unlock_bh(&pool->flow_pool_lock);
 }
 
 /**