smsc95xx: fix register dump of last register

This patch fixes the ethtool register dump for smsc95xx to dump
all 4 bytes of the final register (COE_CR) instead of just the
first byte.
Signed-off-by: Steve Glendinning <steve.glendinning@shawell.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/usb/smsc95xx.c

@@ -691,7 +691,7 @@ static int smsc95xx_ethtool_set_eeprom(struct net_device *netdev,
 static int smsc95xx_ethtool_getregslen(struct net_device *netdev)
 {
 	/* all smsc95xx registers */
-	return COE_CR - ID_REV + 1;
+	return COE_CR - ID_REV + sizeof(u32);
 }
 
 static void