comp: export() doesnt need buf if there are no functions
comp: export() doesnt need buf if there are no functions

This commit removes an "unused variable" compiler warning when compiling
comps without functions, such as mesa_7i65.

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