lldpd should not open a tfport if the dpd link doesn't exist

[Nieuwejaar]

After restarting dpd, the qsfp0/0 uplink was not recreated by RPW. Despite that, lldpd continued to listen on tfportqsfp0_0, which prevented tfportd from cleaning up the link:

root@oxz_switch1:~# dladm show-tfport tfportqsfp0_0                                                                  
LINK        SOURCE      PORT        MACADDRESS                                                                       
tfportqsfp0_0 tfpkt0    320         a8:40:25:5:6:23                                                                  
root@oxz_switch1:~# dladm delete-tfport tfportqsfp0_0                                                                
dladm: tfport deletion failed: link busy
root@oxz_switch1:~# svcadm disable lldpd                                                                             
root@oxz_switch1:~# dladm delete-tfport tfportqsfp0_0                                                                
root@oxz_switch1:~# 

lldpd should shut down an interface's link thread if its interface goes away.