show_head_ref(): convert local variable "unused" to object_id

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

http-backend.c

@@ -408,10 +408,10 @@ static int show_head_ref(const char *refname, const struct object_id *oid,
 	struct strbuf *buf = cb_data;
 
 	if (flag & REF_ISSYMREF) {
-		unsigned char unused[20];
+		struct object_id unused;
 		const char *target = resolve_ref_unsafe(refname,
 							RESOLVE_REF_READING,
-							unused, NULL);
+							unused.hash, NULL);
 		const char *target_nons = strip_namespace(target);
 
 		strbuf_addf(buf, "ref: %s\n", target_nons);