d/swtpm-tools postinst: create the TSS user if it does not exist

Adapted from tpm-udev [0] which handles that, but it is not really a
hard-requirement for swtpm and TSS_USER is configurable after all
(even if that is mostly used for the test system).

So, create that user and group if it does not exists to avoid errors
and failing installation.

[0]: https://salsa.debian.org/debian/tpm-udev/-/blob/master/debian/tpm-udev.postinst

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
1 file changed