dhcp: disable systemd's dhcp_identifier_set_iaid()

dhcp_identifier_set_iaid() is no longer called. Replace
the code with an assertion and always fail.

The function was already annoying previously, because it would
require udev API to generate the IAID. So, we were already required
to patch this function.
5 jobs for th/internal-dhcp6-iaid in 0 seconds (queued for 75 minutes and 19 seconds)
Status Job ID Name Coverage
  Test
failed #52812
allowed to fail
checkpatch

failed #52813
f28_build_autotools

failed #52814
f28_build_meson

failed #52815
f28_rpm_autotools_dbg

failed #52816
f28_rpm_meson_dbg

 
Name Stage Failure
failed
checkpatch Test There has been a timeout failure or the job got stuck. Check your timeout limits or try again
No job log
failed
f28_build_autotools Test There has been a timeout failure or the job got stuck. Check your timeout limits or try again
No job log
failed
f28_build_meson Test There has been a timeout failure or the job got stuck. Check your timeout limits or try again
No job log
failed
f28_rpm_autotools_dbg Test There has been a timeout failure or the job got stuck. Check your timeout limits or try again
No job log
failed
f28_rpm_meson_dbg Test There has been a timeout failure or the job got stuck. Check your timeout limits or try again
No job log