tools : taskcleaner.sh utility returns always 0 as return code

taskcleaner.sh always returns exit code of 0 even on failure

Change-Id: If0c61616e0c4962ee141baba7eda40341d4f721b
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=910796
Signed-off-by: Ravi Nori <rnori@redhat.com>