lrdp_V2 : Fix for broken lsof.py

in case of task list corruption, lsof is breaking
or stuck in look because of cycle is found in taks list.

use the task list iterator API which is handling all
task list corruption case.

Change-Id: I8f9f89e47307c603ce13a56edecd7c576c80ca61
Signed-off-by: Ankur Bansal <ankban@codeaurora.org>