Since 0e987a1 (am, rebase: teach quiet option, 2009-06-16), git-am
supported the --quiet option, and when told to be quiet, would only
speak on failure. Re-implement this by introducing the say() function,
which works like fprintf_ln(), but would only write to the stream when
state->quiet is false.
Signed-off-by: Paul Tan <pyokagan@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>