LONDON (Reuters) - Willie Walsh, head of the British Airways parent company, has attacked a government-backed rescue of regional UK airline Flybe, calling it a misuse of public funds. Flybe was kept afloat on Tuesday after its shareholders agreed to invest more money while the government provided support, reported to involve the deferral of a tax bill.Walsh, chief executive of British Airways-owner IAG , criticised the government help for a privately-held company, saying the taxpayer was picking..