Log Message:
emulators/qemu: fix crash in slirp:tcp_subr.c

Reported upstream to the qemu and slirp projects (thanks to Marc), fixed in

 https://gitlab.freedesktop.org/slirp/libslirp/-/commit/23db43abdb5740287bbb7cbf5cc99eb22e121298

This adds the corresponding patch for qemu-6.1.0.