red_worker.c: fix marshalling of migration data
red_worker.c: fix marshalling of migration data

fix calling spice_marhsaller_add_ref with memory on stack

freedesktop-unofficial-mirror/spice__spice,SPICE/spice,elmarco/spice,fgouget/spice,mathslinux/spice,alon/spice-server,elmarco/spice,elmarco/spice,freedesktop-unofficial-mirror/spice__spice,SPICE/spice,fgouget/spice,freedesktop-unofficial-mirror/spice__spice,elmarco/spice,fgouget/spice,mathslinux/spice,SPICE/spice,ya-mouse/spice,mathslinux/spice,Fantu/spice,fgouget/spice,elmarco/spice,Fantu/spice,mathslinux/spice,Fantu/spice,alon/spice-server,mathslinux/spice,alon/spice-server,freedesktop-unofficial-mirror/spice__spice,alon/spice-server,ya-mouse/spice,alon/spice-server,freedesktop-unofficial-mirror/spice__spice,ya-mouse/spice,Fantu/spice