L2DB.CheckNonces updates all txs, but should filter by state = pending

[ed255]

var checkNoncesQuery = fmt.Sprintf(`
		UPDATE tx_pool SET
			state = '%s',
			batch_num = %%d
		FROM (VALUES
			(NULL::::BIGINT, NULL::::BIGINT),
			(:idx, :nonce)
		) as updated_acc (idx, nonce)
		WHERE tx_pool.from_idx = updated_acc.idx AND tx_pool.nonce <= updated_acc.nonce;
	`, common.PoolL2TxStateInvalid)

// CheckNonces invalidate txs with nonces that are smaller or equal than their
// respective accounts nonces.  The state of the affected txs will be changed
// from Pending to Invalid
func (l2db *L2DB) CheckNonces(updatedAccounts []common.IdxNonce, batchNum common.BatchNum) (err error) {
	if len(updatedAccounts) == 0 {
		return nil
	}
	// Fill the batch_num in the query with Sprintf because we are using a
	// named query which works with slices, and doens't handle an extra
	// individual argument.
	query := fmt.Sprintf(checkNoncesQuery, batchNum)
	if _, err := sqlx.NamedExec(l2db.db, query, updatedAccounts); err != nil {
		return tracerr.Wrap(err)
	}
	return nil
}