During processing incoming RSET frame chip, possibly due to
its internal timout, can retrnasmit an another RSET which
is next queued for processing in shdlc layer.

In case when we accept processed RSET skip those remaining on
the rcv queue until chip will send it's first S or I frame.
This will mean the chip completed connection as well.
Signed-off-by: Waldemar Rymarkiewicz <waldemar.rymarkiewicz@tieto.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>