init: do not create lat logs when not needed

init: do not create lat logs when not needed

When any of the options disable_lat, disable_slat and disable_clat are
used, there is no need to create the lat log associated with the
disabled latency. In addition, when write_lat_log is also specified,
this change avoids the creation of empty latency log files.

Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Niklas Cassel <niklas.cassel@wdc.com>
Link: https://lore.kernel.org/r/20220117021127.9259-1-damien.lemoal@wdc.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>