tcp_input: on RST+ACK in SYN_SENT, unlock the socket mutex before tcp_drop and leave through .drop_no_socket. tcp_drop frees the socket and locks that mutex itself, so the network thread hung on it. Assisted-by: Claude:claude-opus-5 Reviewed-on: KolibriOS/kolibrios#622 Reviewed-by: hidnplayr <hidnplayr@gmail.com> Reviewed-by: Burer <burer@kolibrios.org> Co-authored-by: Kiril Lipatov <lipatov.kiril@gmail.com>