r8169: replace synchronize_rcu with synchronize_net

rtl8169_hw_reset() may be called under RTNL lock, therefore switch to
synchronize_net().

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/realtek/r8169_main.c

@@ -3929,7 +3929,7 @@ static void rtl8169_tx_clear(struct rtl8169_private *tp)
 static void rtl8169_hw_reset(struct rtl8169_private *tp, bool going_down)
 {
 	/* Give a racing hard_start_xmit a few cycles to complete. */
-	synchronize_rcu();
+	synchronize_net();
 
 	/* Disable interrupts */
 	rtl8169_irq_mask_and_ack(tp);