Fix ptm crash due to NULL portdescr Port description TLV is not mandatory and some LLDP agents might not send it
Fix ptm crash due to NULL portdescr
Port description TLV is not mandatory and some LLDP agents might not send it

Issue#4

benthomasson/ptm,CumulusNetworks/ptm,benthomasson/ptm,CumulusNetworks/ptm,CumulusNetworks/ptm,benthomasson/ptm