Fix error when running 'show lldp table' or 'show lldp neighbor' thro…

…ugh SSH command. (#1067)

The command 'show lldp table/neighbor' always return error message 'the
input device is not a TTY' when running in a SSH command or running with
Ansible. This commit is to fix this issue.

scripts/lldpshow

@@ -79,7 +79,7 @@ class Lldpshow(object):
             lldp_interface_list = lldp_port if lldp_port is not None else self.lldp_interface[lldp_instace_num]
             # In detail mode we will pass interface list (only front ports) and get O/P as plain text
             # and in table format we will get xml output
-            lldp_cmd = 'sudo docker exec -it lldp{} lldpctl '.format(self.lldp_instance[lldp_instace_num]) + (
+            lldp_cmd = 'sudo docker exec -i lldp{} lldpctl '.format(self.lldp_instance[lldp_instace_num]) + (
                 '-f xml' if not lldp_detail_info else lldp_interface_list)
             p = subprocess.Popen(lldp_cmd, stdout=subprocess.PIPE, shell=True)
             (output, err) = p.communicate()