add new interception to check for paced flows

ignore interception for DBG_LOG config of pacer module

this is mainly to avoid panics due to improper accounting at insmod and rmmod
should be fixed in future.

required for the case when txq times out and nic unloads and reloads.
it tries to free up all pkts queued between prod and cons. some of
these maybe our special dummy pkt, which should not be freed until
rmmod.