r8169: more broken register writes workaround

78f1cd02457252e1ffbc6caa44a17424a45286b8 ("fix broken register writes")
does not work for Al Viro's r8169 (XID 18000000).

Signed-off-by: Francois Romieu <romieu@fr.zoreil.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/r8169.c

@@ -2826,8 +2826,13 @@ static void rtl_rar_set(struct rtl8169_private *tp, u8 *addr)
 	spin_lock_irq(&tp->lock);
 
 	RTL_W8(Cfg9346, Cfg9346_Unlock);
+
 	RTL_W32(MAC4, high);
+	RTL_R32(MAC4);
+
 	RTL_W32(MAC0, low);
+	RTL_R32(MAC0);
+
 	RTL_W8(Cfg9346, Cfg9346_Lock);
 
 	spin_unlock_irq(&tp->lock);