device: add missing colon to error line

People are actually hitting this condition, so make it uniform. Also,
change a printf into a println, to match the other conventions.

Signed-off-by: Jason A. Donenfeld <[email protected]>

Author: zx2c4

device/device.go

@@ -158,7 +158,7 @@ func deviceUpdateState(device *Device) {
 	switch newIsUp {
 	case true:
 		if err := device.BindUpdate(); err != nil {
-			device.log.Error.Printf("Unable to update bind: %v\n", err)
+			device.log.Error.Println("Unable to update bind:", err)
 			device.isUp.Set(false)
 			break
 		}

device/send.go

@@ -174,7 +174,7 @@ func (peer *Peer) SendHandshakeInitiation(isRetry bool) error {
 
 	err = peer.SendBuffer(packet)
 	if err != nil {
-		peer.device.log.Error.Println(peer, "- Failed to send handshake initiation", err)
+		peer.device.log.Error.Println(peer, "- Failed to send handshake initiation:", err)
 	}
 	peer.timersHandshakeInitiated()
 
@@ -212,7 +212,7 @@ func (peer *Peer) SendHandshakeResponse() error {
 
 	err = peer.SendBuffer(packet)
 	if err != nil {
-		peer.device.log.Error.Println(peer, "- Failed to send handshake response", err)
+		peer.device.log.Error.Println(peer, "- Failed to send handshake response:", err)
 	}
 	return err
 }