ipfw: line up `ipfw -t list` with and without timestamp

ipfw: line up `ipfw -t list` with and without timestamp

From the PR:
    When I run `ipfw -t list` on release/12 or current, I get misaligned
    output between lines that do and do not have a last match timestamp,
    like so:

    00100 Tue Aug 11 03:03:26 2020 allow ip from any to any via lo0
    00200                         deny ip from any to 127.0.0.0/8

    (specifically, the "allow" and "deny" strings do not line up)

PR:		248608
Submitted by:	Taylor Stearns
MFC after:	3 days