smsc75xx: replace 0xffff with PHY_INT_SRC_CLEAR_ALL

This patch defines PHY_INT_SRC_CLEAR_ALL to replace the value 0xffff
in order to be more self-documenting.

This patch should make no functional change, it is purely cosmetic.
Signed-off-by: Steve Glendinning <steve.glendinning@shawell.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/usb/smsc75xx.c

@@ -511,7 +511,8 @@ static int smsc75xx_link_reset(struct usbnet *dev)
 	/* read and write to clear phy interrupt status */
 	ret = smsc75xx_mdio_read(dev->net, mii->phy_id, PHY_INT_SRC);
 	check_warn_return(ret, "Error reading PHY_INT_SRC");
-	smsc75xx_mdio_write(dev->net, mii->phy_id, PHY_INT_SRC, 0xffff);
+	smsc75xx_mdio_write(dev->net, mii->phy_id, PHY_INT_SRC,
+		PHY_INT_SRC_CLEAR_ALL);
 
 	ret = smsc75xx_write_reg(dev, INT_STS, INT_STS_CLEAR_ALL);
 	check_warn_return(ret, "Error writing INT_STS");

drivers/net/usb/smsc75xx.h

@@ -388,6 +388,7 @@
 #define PHY_INT_SRC_ANEG_COMP		((u16)0x0040)
 #define PHY_INT_SRC_REMOTE_FAULT	((u16)0x0020)
 #define PHY_INT_SRC_LINK_DOWN		((u16)0x0010)
+#define PHY_INT_SRC_CLEAR_ALL		((u16)0xffff)
 
 #define PHY_INT_MASK			(30)
 #define PHY_INT_MASK_ENERGY_ON		((u16)0x0080)