diff --stat: do not do its own three-dashes.

I missed that "git-diff-* --stat" spits out three-dash separator
on its own without being asked.  Remove it.

When we output commit log followed by diff, perhaps --patch-with-stat,
for downstream consumer, we _would_ want the three-dash between
the message and the diff material, but that logic belongs to the
caller, not diff generator.

Signed-off-by: Junio C Hamano <junkio@cox.net>

diff.c

@@ -245,8 +245,6 @@ static void show_stats(struct diffstat_t* data)
 	if (data->nr == 0)
 		return;
 
-	printf("---\n");
-
 	for (i = 0; i < data->nr; i++) {
 		struct diffstat_file *file = data->files[i];
 

git.c

@@ -388,8 +388,10 @@ static int cmd_log(int argc, const char **argv, char **envp)
 		pretty_print_commit(commit_format, commit, ~0, buf,
 				    LOGSIZE, abbrev);
 		printf("%s\n", buf);
-		if (do_diff)
+		if (do_diff) {
+			printf("---\n");
 			log_tree_commit(&opt, commit);
+		}
 		shown = 1;
 		free(commit->buffer);
 		commit->buffer = NULL;