analyze: do not print timestamps before "start of userspace"

[keszybz]

We have the following timestamp status:

$ systemctl show systemd-fsck-root.service | grep InactiveExitTimestamp
InactiveExitTimestamp=Thu 2023-11-02 12:27:24 CET
InactiveExitTimestampMonotonic=15143158

$ systemctl show | grep UserspaceTimestamp
UserspaceTimestamp=Thu 2023-11-02 12:27:25 CET
UserspaceTimestampMonotonic=15804273

i.e. UserspaceTimestamp is before InactiveExit of systemd-fsck-root.service. This is fine, but on display, we'd subtract those values and print a huge negative value bogusly:

$ build/systemd-analyze critical-chain systemd-remount-fs.service
The time when unit became active or started is printed after the "@" character.
The time the unit took to start is printed after the "+" character.

systemd-remount-fs.service +137ms
└─systemd-fsck-root.service @584542y 2w 2d 20h 1min 48.890s +45ms
└─systemd-journald.socket
└─system.slice
└─-.slice

In fact, list_dependencies_print() already had a branch where the check that 'times->activating > boot->userspace_time', but it didn't cover all cases. So make it cover both branches, and also change to '>=', since it's fine if something happened with the same timestamp.

With the patch:

$ build/systemd-analyze critical-chain systemd-remount-fs.service
The time when unit became active or started is printed after the "@" character.
The time the unit took to start is printed after the "+" character.

systemd-remount-fs.service +42ms
└─systemd-fsck-root.service
└─systemd-journald.socket
└─system.slice
└─-.slice

Fixes #17191.

[github-actions]

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