enetc: convert to schedule_work()

Convert system_wq queue_work() to schedule_work() which is
a wrapper around it, since the former is a rare construct.

Fixes: 7294380c ("enetc: support PTP Sync packet one-step timestamping")
Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/freescale/enetc/enetc.c

@@ -552,7 +552,7 @@ static bool enetc_clean_tx_ring(struct enetc_bdr *tx_ring, int napi_budget)
 				 * timestamping packet. And send one skb in
 				 * tx_skbs queue if has.
 				 */
-				queue_work(system_wq, &priv->tx_onestep_tstamp);
+				schedule_work(&priv->tx_onestep_tstamp);
 			} else if (unlikely(do_twostep_tstamp)) {
 				enetc_tstamp_tx(skb, tstamp);
 				do_twostep_tstamp = false;