stat: reduce arguments of add_log_sample()

stat: reduce arguments of add_log_sample()

The number of arguments of add_log_sample() has increased as fields get
added to the log file format. Five parameters of them (data, ddir, bs,
offset and priority) are passed to __add_log_sample(). This makes the
function look more complicated and log field addition harder. To
simplify the function, pack the five arguments into the new struct
log_sample.

Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Link: https://lore.kernel.org/r/20240829085826.999859-3-shinichiro.kawasaki@wdc.com
Signed-off-by: Vincent Fu <vincent.fu@samsung.com>