Merge branch 'pktgen-Behavior-flags-fixes'

Dmitry Safonov says:

====================
pktgen: Behavior flags fixes

v2:
  o fixed a nitpick from David Miller

There are a bunch of fixes/cleanups/Documentations.
Diffstat says for itself, regardless added docs and missed flag
parameters.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>