The VLIB_FRAME_NO_FREE_AFTER_DISPATCH flag is not preserved when cloning
next_frames, as a result VLIB_FRAME_FREE_AFTER_DISPATCH can
erroneously be set for a frame (see vlib_get_next_frame_internal())
Change-Id: Ice1d7ddcb807e1168aa0c157d9474be492d102c2
Signed-off-by: Nikhil P Rao <nikhil.rao@intel.com>