all: use gometalinter.v2, fix new gosimple issues (#15650)

p2p/discv5/net.go

@@ -684,7 +684,7 @@ func (net *Network) refresh(done chan<- struct{}) {
 		seeds = net.nursery
 	}
 	if len(seeds) == 0 {
-		log.Trace(fmt.Sprint("no seed nodes found"))
+		log.Trace("no seed nodes found")
 		close(done)
 		return
 	}

p2p/discv5/ntp.go

@@ -54,10 +54,10 @@ func checkClockDrift() {
 		howtofix := fmt.Sprintf("Please enable network time synchronisation in system settings")
 		separator := strings.Repeat("-", len(warning))
 
-		log.Warn(fmt.Sprint(separator))
-		log.Warn(fmt.Sprint(warning))
-		log.Warn(fmt.Sprint(howtofix))
-		log.Warn(fmt.Sprint(separator))
+		log.Warn(separator)
+		log.Warn(warning)
+		log.Warn(howtofix)
+		log.Warn(separator)
 	} else {
 		log.Debug(fmt.Sprintf("Sanity NTP check reported %v drift, all ok", drift))
 	}

p2p/discv5/ticket.go

@@ -398,12 +398,12 @@ func (s *ticketStore) nextRegisterableTicket() (t *ticketRef, wait time.Duration
 			//s.removeExcessTickets(topic)
 			if len(tickets.buckets) != 0 {
 				empty = false
-				if list := tickets.buckets[bucket]; list != nil {
-					for _, ref := range list {
-						//debugLog(fmt.Sprintf(" nrt bucket = %d node = %x sn = %v wait = %v", bucket, ref.t.node.ID[:8], ref.t.serial, time.Duration(ref.topicRegTime()-now)))
-						if nextTicket.t == nil || ref.topicRegTime() < nextTicket.topicRegTime() {
-							nextTicket = ref
-						}
+
+				list := tickets.buckets[bucket]
+				for _, ref := range list {
+					//debugLog(fmt.Sprintf(" nrt bucket = %d node = %x sn = %v wait = %v", bucket, ref.t.node.ID[:8], ref.t.serial, time.Duration(ref.topicRegTime()-now)))
+					if nextTicket.t == nil || ref.topicRegTime() < nextTicket.topicRegTime() {
+						nextTicket = ref
 					}
 				}
 			}