ui-log: Do not always emit decoration span

The decoration span does not need to be emited if there aren't
any decorations to show.  This modification saves slightly
on bandwidth.

Signed-off-by: Tim Nordell <tim.nordell@logicpd.com>

ui-log.c

@@ -61,6 +61,8 @@ void show_commit_decorations(struct commit *commit)
 
 	buf[sizeof(buf) - 1] = 0;
 	deco = get_name_decoration(&commit->object);
+	if (!deco)
+		return;
 	html("<span class='decoration'>");
 	while (deco) {
 		if (starts_with(deco->name, "refs/heads/")) {