tun2socks: fix typo which might cause a crash if tcp_close() failed due to out of memory (theoretical bug only). Found  with the help of clang static analyzer.
tun2socks: fix typo which might cause a crash if tcp_close() failed due to out of memory (theoretical bug only). Found 
with the help of clang static analyzer.

Ernillew/badvpn,Ernillew/badvpn,Ernillew/badvpn,Ernillew/badvpn,Ernillew/badvpn