r8169: improve rtl8169_mark_to_asic

Let the compiler decide about inlining, and as confirmed by Eric it's
better to use WRITE_ONCE here to ensure that the descriptor ownership
is transferred to NIC immediately.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/realtek/r8169_main.c

@@ -3824,15 +3824,14 @@ static int rtl8169_change_mtu(struct net_device *dev, int new_mtu)
 	return 0;
 }
 
-static inline void rtl8169_mark_to_asic(struct RxDesc *desc)
+static void rtl8169_mark_to_asic(struct RxDesc *desc)
 {
 	u32 eor = le32_to_cpu(desc->opts1) & RingEnd;
 
 	desc->opts2 = 0;
 	/* Force memory writes to complete before releasing descriptor */
 	dma_wmb();
-
-	desc->opts1 = cpu_to_le32(DescOwn | eor | R8169_RX_BUF_SIZE);
+	WRITE_ONCE(desc->opts1, cpu_to_le32(DescOwn | eor | R8169_RX_BUF_SIZE));
 }
 
 static struct page *rtl8169_alloc_rx_data(struct rtl8169_private *tp,