  Fix a crash in tcp_input(), that happens when mbuf has a fwd_tag on it, but later after processing and freeing the tag, we need to jump back again to the findpcb label. Since the fwd_tag pointer wasn't NULL we tried to process and free the tag for second time.
  Fix a crash in tcp_input(), that happens when mbuf has a fwd_tag on it,
but later after processing and freeing the tag, we need to jump back again
to the findpcb label. Since the fwd_tag pointer wasn't NULL we tried to
process and free the tag for second time.

Reported & tested by:	Pawel Tyll <ptyll nitronet.pl>
MFC after:		3 days

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase