SEBA-758 send periodic port stats to voltha
SEBA-790 get flow, gemport, and tcont information through API
fix lint errors

Change-Id: I10909e1992eba71d8e54c976ccbcea8778e35539
diff --git a/device/utils.go b/device/utils.go
index 7e0eca3..2d4cc28 100644
--- a/device/utils.go
+++ b/device/utils.go
@@ -17,19 +17,17 @@
 package device
 
 import (
-	"fmt"
-
 	"github.com/opencord/voltha-bbsim/common/logger"
 	log "github.com/sirupsen/logrus"
 	"strconv"
 )
 
+// OnuToSn returns serial number in string format for given ONU
 func OnuToSn(onu *Onu) string {
-	// FIXME
-	// see https://github.com/opencord/voltha/blob/master/voltha/adapters/openolt/openolt_device.py#L929-L943
-	return string(onu.SerialNumber.VendorId) + "00000" + fmt.Sprint(onu.IntfID) + "0" + fmt.Sprintf("%x", onu.OnuID-1)
+	return string(onu.SerialNumber.VendorId) + ConvB2S(onu.SerialNumber.VendorSpecific)
 }
 
+// LoggerWithOnu method logs ONU fields
 func LoggerWithOnu(onu *Onu) *log.Entry {
 
 	if onu == nil {
@@ -39,12 +37,13 @@
 
 	return logger.GetLogger().WithFields(log.Fields{
 		"serial_number": OnuToSn(onu),
-		"interfaceId":   onu.IntfID,
-		"onuId":         onu.OnuID,
-		"oltId":         onu.OltID,
+		"interfaceID":   onu.IntfID,
+		"onuID":         onu.OnuID,
+		"oltID":         onu.OltID,
 	})
 }
 
+// ConvB2S converts byte array to string
 func ConvB2S(b []byte) string {
 	s := ""
 	for _, i := range b {