When cf0adba788 ("Store peeled refs in packed-refs file.",
2006-11-19) made the command to die with a message on error even
when --quiet is passed, it left the comment to say it changed the
semantics. But that kind of information belongs to the log message,
not in-code comment. Besides, the behaviour after the change has
been the established one for the past 10 years ;-)
Signed-off-by: Junio C Hamano <gitster@pobox.com>