avformat/tcp: TCP Protocol: fix descriptor leak on listen and interrupt

If we try to listen on TCP port and ff_listen() fails on
interrupt callback socket (bind) descriptor overwrites and
does not closed at all.

As a result, we can't rebind to the same port.

Reviewed-by: Stephan Holljes <klaxa1337@googlemail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
