show_head_ref(): do not shadow name of argument

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

http-backend.c

@@ -416,8 +416,8 @@ static int show_head_ref(const char *name, const unsigned char *sha1,
 	struct strbuf *buf = cb_data;
 
 	if (flag & REF_ISSYMREF) {
-		unsigned char sha1[20];
-		const char *target = resolve_ref_unsafe(name, sha1, 1, NULL);
+		unsigned char unused[20];
+		const char *target = resolve_ref_unsafe(name, unused, 1, NULL);
 		const char *target_nons = strip_namespace(target);
 
 		strbuf_addf(buf, "ref: %s\n", target_nons);