The logfile format which is generated with '-l' and '-L' consists of an
absolute epoch timestamp. In some use cases (e.g. for documentation) a
zero relative timestamp can be useful which was only configurable with
the '-tz' option for the classic output.
'-tz' and '-ta' are now valid options for the logfile format.
Signed-off-by: Richard Young <code@richyoung.ca>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
