message: rename NewMsg to New

Should have done this when relocating this from container. Now is a good time to rename it before v0.3.x.

Signed-off-by: Ophestra <cat@gensokyo.uk>

cmd/hakurei/main.go

@@ -32,7 +32,7 @@ func main() {
 
 	log.SetPrefix("hakurei: ")
 	log.SetFlags(0)
-	msg := message.NewMsg(log.Default())
+	msg := message.New(log.Default())
 
 	early := earlyHardeningErrs{
 		yamaLSM:  container.SetPtracer(0),