builtin/pack-objects: report reused packfile objects

To see when packfile reuse kicks in or not, it is useful to
show reused packfile objects statistics in the output of
upload-pack.

Helped-by: James Ramsay <james@jramsay.com.au>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/pack-objects.c

@@ -3525,7 +3525,9 @@ int cmd_pack_objects(int argc, const char **argv, const char *prefix)
 	if (progress)
 		fprintf_ln(stderr,
 			   _("Total %"PRIu32" (delta %"PRIu32"),"
-			     " reused %"PRIu32" (delta %"PRIu32")"),
-			   written, written_delta, reused, reused_delta);
+			     " reused %"PRIu32" (delta %"PRIu32"),"
+			     " pack-reused %"PRIu32),
+			   written, written_delta, reused, reused_delta,
+			   reuse_packfile_objects);
 	return 0;
 }