ganeti.utils.log_unittest.py: replace file with FileIO
ganeti.utils.log_unittest.py: replace file with FileIO

Under Python 3 there is no file class anymore; use io.FileIO instead.

Signed-off-by: Apollon Oikonomopoulos <ed81ed0a45ccd5c8869bda52e38353a6299ee39e@dmesg.gr>

mbakke/ganeti,mbakke/ganeti,mbakke/ganeti,ganeti/ganeti,ganeti/ganeti,ganeti/ganeti