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>
diff --git a/drivers/net/r8169.c b/drivers/net/r8169.c
index 2b54389..4748c21 100644
--- a/drivers/net/r8169.c
+++ b/drivers/net/r8169.c
@@ -2826,8 +2826,13 @@
 	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);