fix compile on kernels 2.6.24 and older
fix compile on kernels 2.6.24 and older

In 2.6.25, the items in 'struct pt_regs' had their names unified on x86
and amd64, so that the instruction pointer was 'ip' on both systems (and
actually on a range of other architectures as well).  In the bad old
days, struct pt_regs had differently named fields on the two
architectures in question, eip and rip.  Accomodate the different
possibilities.

cnc-club/linuxcnc,araisrobo/machinekit,ikcalB/linuxcnc-mirror,kinsamanka/machinekit,unseenlaser/linuxcnc,araisrobo/machinekit,kinsamanka/machinekit,ArcEye/machinekit-testing,mhaberler/machinekit,RunningLight/machinekit,RunningLight/machinekit,aschiffler/linuxcnc,strahlex/machinekit,ArcEye/MK-Qt5,strahlex/machinekit,cdsteinkuehler/linuxcnc,Cid427/machinekit,ArcEye/machinekit-testing,araisrobo/linuxcnc,araisrobo/machinekit,aschiffler/linuxcnc,kinsamanka/machinekit,strahlex/machinekit,ArcEye/MK-Qt5,strahlex/machinekit,mhaberler/machinekit,cdsteinkuehler/MachineKit,ArcEye/MK-Qt5,unseenlaser/machinekit,aschiffler/linuxcnc,cdsteinkuehler/MachineKit,bmwiedemann/linuxcnc-mirror,bmwiedemann/linuxcnc-mirror,araisrobo/linuxcnc,ArcEye/machinekit-testing,bmwiedemann/linuxcnc-mirror,ikcalB/linuxcnc-mirror,bmwiedemann/linuxcnc-mirror,Cid427/machinekit,EqAfrica/machinekit,unseenlaser/linuxcnc,cnc-club/linuxcnc,EqAfrica/machinekit,EqAfrica/machinekit,ArcEye/MK-Qt5,EqAfrica/machinekit,bobvanderlinden/machinekit,cnc-club/linuxcnc,Cid427/machinekit,araisrobo/linuxcnc,unseenlaser/machinekit,ianmcmahon/linuxcnc-mirror,ArcEye/machinekit-testing,araisrobo/linuxcnc,bobvanderlinden/machinekit,kinsamanka/machinekit,ikcalB/linuxcnc-mirror,araisrobo/machinekit,kinsamanka/machinekit,EqAfrica/machinekit,narogon/linuxcnc,araisrobo/machinekit,ArcEye/machinekit-testing,bmwiedemann/linuxcnc-mirror,cdsteinkuehler/MachineKit,ArcEye/machinekit-testing,cdsteinkuehler/linuxcnc,ianmcmahon/linuxcnc-mirror,EqAfrica/machinekit,ArcEye/machinekit-testing,cnc-club/linuxcnc,bobvanderlinden/machinekit,ianmcmahon/linuxcnc-mirror,EqAfrica/machinekit,Cid427/machinekit,RunningLight/machinekit,araisrobo/linuxcnc,RunningLight/machinekit,unseenlaser/machinekit,araisrobo/machinekit,cdsteinkuehler/linuxcnc,cdsteinkuehler/MachineKit,jaguarcat79/ILC-with-LinuxCNC,ArcEye/MK-Qt5,ArcEye/MK-Qt5,cnc-club/linuxcnc,bobvanderlinden/machinekit,ArcEye/machinekit-testing,mhaberler/machinekit,bobvanderlinden/machinekit,jaguarcat79/ILC-with-LinuxCNC,Cid427/machinekit,strahlex/machinekit,narogon/linuxcnc,unseenlaser/linuxcnc,jaguarcat79/ILC-with-LinuxCNC,ianmcmahon/linuxcnc-mirror,ianmcmahon/linuxcnc-mirror,narogon/linuxcnc,ArcEye/MK-Qt5,kinsamanka/machinekit,ikcalB/linuxcnc-mirror,unseenlaser/machinekit,cdsteinkuehler/MachineKit,unseenlaser/machinekit,cdsteinkuehler/linuxcnc,RunningLight/machinekit,araisrobo/machinekit,mhaberler/machinekit,kinsamanka/machinekit,cdsteinkuehler/linuxcnc,unseenlaser/machinekit,mhaberler/machinekit,Cid427/machinekit,ikcalB/linuxcnc-mirror,ianmcmahon/linuxcnc-mirror,aschiffler/linuxcnc,ikcalB/linuxcnc-mirror,cdsteinkuehler/MachineKit,ianmcmahon/linuxcnc-mirror,strahlex/machinekit,cnc-club/linuxcnc,ArcEye/MK-Qt5,unseenlaser/machinekit,bobvanderlinden/machinekit,ikcalB/linuxcnc-mirror,Cid427/machinekit,Cid427/machinekit,bobvanderlinden/machinekit,RunningLight/machinekit,mhaberler/machinekit,jaguarcat79/ILC-with-LinuxCNC,cdsteinkuehler/linuxcnc,narogon/linuxcnc,EqAfrica/machinekit,strahlex/machinekit,RunningLight/machinekit,araisrobo/machinekit,mhaberler/machinekit,aschiffler/linuxcnc,kinsamanka/machinekit,bobvanderlinden/machinekit,mhaberler/machinekit,unseenlaser/linuxcnc,araisrobo/machinekit,cnc-club/linuxcnc,unseenlaser/linuxcnc,bmwiedemann/linuxcnc-mirror,unseenlaser/machinekit,RunningLight/machinekit,bmwiedemann/linuxcnc-mirror,jaguarcat79/ILC-with-LinuxCNC,narogon/linuxcnc