Execute ipset command using check_exit_code

Execute ipset command using check_exit_code

When l2 agent execute ipset command, we should pass
parameter 'check_exit_code' to self.execute acording to
action.
The intention is to safely fail if we try to destroy a
non existing set, or delete a non existing member.
Otherwise the agent gets stuck in a loop if such situation
happens. Such kind of event would be logged as errors.

Change-Id: If67330523d114d6da13d0280851e7138a51d08f7
Closes-bug: #1497074