r8169: revert bogus BMCR reset

Added during bf793295

The current code requests a reset but prohibits autoneg, 1000 Mb/s,
100 Mb/s and full duplex. The 8168 does not like it at all.
Signed-off-by: Francois Romieu <romieu@fr.zoreil.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

drivers/net/r8169.c

@@ -572,8 +572,8 @@ static void rtl8169_xmii_reset_enable(void __iomem *ioaddr)
 {
 	unsigned int val;
 
-	mdio_write(ioaddr, MII_BMCR, BMCR_RESET);
-	val = mdio_read(ioaddr, MII_BMCR);
+	val = mdio_read(ioaddr, MII_BMCR) | BMCR_RESET;
+	mdio_write(ioaddr, MII_BMCR, val & 0xffff);
 }
 
 static void rtl8169_check_link_status(struct net_device *dev,