udf: Convert udf_disk_stamp_to_time() to use mktime64()

Convert udf_disk_stamp_to_time() to use mktime64() to simplify the code.
As a bonus we get working timestamp conversion for dates before epoch
and after 2038 (both of which are allowed by UDF standard).

Signed-off-by: Jan Kara <jack@suse.cz>
1 file changed