od: code shrink, fix "od --traditional FILE"

function                                             old     new   delta
parse_old_offset                                     107     125     +18
packed_usage                                       28715   28691     -24
od_main                                             2312    2275     -37

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
3 files changed