drivers: nxp_enet: Fix tx error handling

The code path for error handling and timestamping in tx path
was meant to be identical in function to old eth_mcux driver,
but there is actually a discrepancy causing no error handling
for timestamped frames, fix it.

Signed-off-by: Declan Snyder <declan.snyder@nxp.com>

drivers/ethernet/nxp_enet/eth_nxp_enet.c

@@ -224,15 +224,16 @@ static int eth_nxp_enet_tx(const struct device *dev, struct net_pkt *pkt)
 
 	ret = ENET_SendFrame(data->base, &data->enet_handle, data->tx_frame_buf,
 			     total_len, RING_ID, frame_is_timestamped, pkt);
-	if (ret == kStatus_Success) {
+
+	if (ret != kStatus_Success) {
+		LOG_ERR("ENET_SendFrame error: %d", ret);
+		ENET_ReclaimTxDescriptor(data->base, &data->enet_handle, RING_ID);
+		ret = -EIO;
 		goto exit;
 	}
 
 	if (frame_is_timestamped) {
 		eth_wait_for_ptp_ts(dev, pkt);
-	} else {
-		LOG_ERR("ENET_SendFrame error: %d", ret);
-		ENET_ReclaimTxDescriptor(data->base, &data->enet_handle, RING_ID);
 	}
 
 exit: