error_routine: use parent's stderr if exec fails The new process's error output may be redirected elsewhere, but if the exec fails, output should still go to the parent's stderr. This has already been done for the die_routine. Do the same for error_routine. Signed-off-by: Clemens Buchacher <drizzd@aon.at> Signed-off-by: Junio C Hamano <gitster@pobox.com>