last: not all hostnames are shown in the last column with --hostlast

[cakebaker]

When using -a/--hostlast, not all hostnames are shown in the last column (see the last two lines):

$ cargo run last -a -n 10
dho      pts/4        Wed Feb  5 13:34   still logged in :1
dho      pts/3        Wed Feb  5 13:34   still logged in :1
dho      pts/5        Wed Feb  5 13:34   still logged in :1
dho      pts/1        Wed Feb  5 13:34   still logged in :1
dho      pts/2        Wed Feb  5 13:34   still logged in :1
dho      pts/0        Wed Feb  5 13:34   still logged in :1
dho      tty1         Wed Feb  5 13:34   still logged in
reboot   system boot  Wed Feb  5 13:33   still running 6.13.1-arch1-1
dho      pts/2        Wed Feb  5 06:27 - down   :1 (05:28)
dho      pts/5        Wed Feb  5 06:27 - down   :1 (05:28)

With last from util-linux:

$ last -a -n 10
dho      pts/4        Wed Feb  5 13:34   still logged in    :1
dho      pts/3        Wed Feb  5 13:34   still logged in    :1
dho      pts/5        Wed Feb  5 13:34   still logged in    :1
dho      pts/1        Wed Feb  5 13:34   still logged in    :1
dho      pts/2        Wed Feb  5 13:34   still logged in    :1
dho      pts/0        Wed Feb  5 13:34   still logged in    :1
dho      tty1         Wed Feb  5 13:34   still logged in
reboot   system boot  Wed Feb  5 13:33   still running      6.13.1-arch1-1
dho      pts/2        Wed Feb  5 06:27 - down   (05:28)     :1
dho      pts/5        Wed Feb  5 06:27 - down   (05:28)     :1