to_ssh_rtl
struct ssh_rtl *rtl = to_ssh_rtl(work, tx.work);
struct ssh_rtl *rtl = to_ssh_rtl(work, rtx_timeout.reaper.work);
struct ssh_rtl *rtl = to_ssh_rtl(p, ptl);
return likely(ptl) ? to_ssh_rtl(ptl, ptl) : NULL;