r8169: fix r8101 quirk dupe

Noticed by Vincent Pelletier <plr.vincent@gmail.com>.
Signed-off-by: NFrancois Romieu <romieu@fr.zoreil.com>
Cc: Edward Hsu <edward_hsu@realtek.com.tw>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/r8169.c

@@ -2757,7 +2757,7 @@ static void rtl_hw_start_8168(struct net_device *dev)
 	EnableBist | \
 	Mac_dbgo_oe | \
 	Force_half_dup | \
-	Force_half_dup | \
+	Force_rxflow_en | \
 	Force_txflow_en | \
 	Cxpl_dbg_sel | \
 	ASF | \