shortlog: extract `shortlog_finish_setup()`

Extract a function which finishes setting up the shortlog struct for
use. The caller in `make_cover_letter()` does not care about trailer
sorting, so it isn't strictly necessary to add a call there in this
patch.

But the next patch will add additional functionality to the new
`shortlog_finish_setup()` function, which the caller in
`make_cover_letter()` will care about.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/shortlog.h b/shortlog.h
index 4850a8c30f..28d04f951a 100644
--- a/shortlog.h
+++ b/shortlog.h
@@ -33,6 +33,7 @@ struct shortlog {
 };
 
 void shortlog_init(struct shortlog *log);
+void shortlog_finish_setup(struct shortlog *log);
 
 void shortlog_add_commit(struct shortlog *log, struct commit *commit);