multi: rename chan DB Open method to OpenForTesting

rpcserver_test.go

@@ -41,11 +41,7 @@ func (m *mockDataParser) InlineParseCustomData(msg proto.Message) error {
 
 func TestAuxDataParser(t *testing.T) {
 	// We create an empty channeldb, so we can fetch some channels.
-	cdb, err := channeldb.Open(t.TempDir())
-	require.NoError(t, err)
-	t.Cleanup(func() {
-		require.NoError(t, cdb.Close())
-	})
+	cdb := channeldb.OpenForTesting(t, t.TempDir())
 
 	r := &rpcServer{
 		server: &server{