Clean up some memory leaks

src/remote.c

@@ -1255,6 +1255,7 @@ static int opportunistic_updates(const git_remote *remote, git_vector *refs, con
 
 		error = git_reference_create(&ref, remote->repo, refname.ptr, &head->oid, true, sig, msg);
 		git_buf_free(&refname);
+		git_reference_free(ref);
 
 		if (error < 0)
 			return error;

tests/index/cache.c

@@ -170,6 +170,8 @@ void test_index_cache__two_levels(void)
 	tree_cache = git_tree_cache_get(index->tree, "subdir");
 	cl_assert(tree_cache);
 	cl_assert_equal_i(1, tree_cache->entry_count);
+
+	git_index_free(index);
 }
 
 void test_index_cache__read_tree_children(void)