triedb/pathdb: no need to reread metadata again

[jsvisa]

The metadata was read and checked before

go-ethereum/triedb/pathdb/history_reader.go

Lines 333 to 340 in 0153788

	metadata := loadIndexMetadata(r.disk)
	if metadata == nil || metadata.Last < lastID {
	indexed := "null"
	if metadata != nil {
	indexed = fmt.Sprintf("%d", metadata.Last)
	}
	return nil, fmt.Errorf("state history is not fully indexed, requested: %d, indexed: %s", stateID, indexed)
	}

So I think there's no need to read the metadata again.