r8169: add checking driver's runtime pm status in rtl8169_get_ethtool_stats()

Not to call rtl8169_update_counters() to dump tally counter when driver
is in runtime suspend state.

Calling rtl8169_update_counters() in runtime suspend state will produce
warning message "rtl_counters_cond == 1 (loop: 1000, delay: 10)".
Signed-off-by: Chunhao Lin <hau@realtek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/realtek/r8169.c

@@ -2308,11 +2308,17 @@ static void rtl8169_get_ethtool_stats(struct net_device *dev,
 				      struct ethtool_stats *stats, u64 *data)
 {
 	struct rtl8169_private *tp = netdev_priv(dev);
+	struct device *d = &tp->pci_dev->dev;
 	struct rtl8169_counters *counters = tp->counters;
 
 	ASSERT_RTNL();
 
-	rtl8169_update_counters(dev);
+	pm_runtime_get_noresume(d);
+
+	if (pm_runtime_active(d))
+		rtl8169_update_counters(dev);
+
+	pm_runtime_put_noidle(d);
 
 	data[0] = le64_to_cpu(counters->tx_packets);
 	data[1] = le64_to_cpu(counters->rx_packets);