Fix linting for TTL

See https://go.googlesource.com/lint/+/refs/heads/master/lint.go#797

Signed-off-by: Roger Pueyo Centelles <rpueyo@ac.upc.edu>

cmd/ping/ping.go

@@ -66,7 +66,7 @@ func main() {
 
 	pinger.OnRecv = func(pkt *ping.Packet) {
 		fmt.Printf("%d bytes from %s: icmp_seq=%d time=%v ttl=%v\n",
-			pkt.Nbytes, pkt.IPAddr, pkt.Seq, pkt.Rtt, pkt.Ttl)
+			pkt.Nbytes, pkt.IPAddr, pkt.Seq, pkt.Rtt, pkt.TTL)
 	}
 	pinger.OnFinish = func(stats *ping.Statistics) {
 		fmt.Printf("\n--- %s ping statistics ---\n", stats.Addr)

ping.go

@@ -179,7 +179,7 @@ type Packet struct {
 	Seq int
 
 	// TTL is the Time To Live on the packet.
-	Ttl int
+	TTL int
 }
 
 // Statistics represent the stats of a currently running or finished
@@ -470,7 +470,7 @@ func (p *Pinger) processPacket(recv *packet) error {
 		Nbytes: recv.nbytes,
 		IPAddr: p.ipaddr,
 		Addr:   p.addr,
-		Ttl:    recv.ttl,
+		TTL:    recv.ttl,
 	}
 
 	switch pkt := m.Body.(type) {