Avoid division by zero if no video memory is available.
Avoid division by zero if no video memory is available.

sklnet/DirectFB,deniskropp/DirectFB,lancebaiyouview/DirectFB,mtsekm/test,DirectFB/directfb,kevleyski/directfb,kaostao/directfb,kevleyski/DirectFB-1,lancebaiyouview/DirectFB,dfbdok/DirectFB1,Distrotech/DirectFB,dfbdok/DirectFB1,lancebaiyouview/DirectFB,kevleyski/directfb,Distrotech/DirectFB,deniskropp/DirectFB,sklnet/DirectFB,kevleyski/directfb,mtsekm/test,jcdubois/DirectFB,djbclark/directfb-core-DirectFB,mtsekm/test,DirectFB/directfb,kevleyski/DirectFB-1,dfbdok/DirectFB1,DirectFB/directfb,jcdubois/DirectFB,djbclark/directfb-core-DirectFB,djbclark/directfb-core-DirectFB,djbclark/directfb-core-DirectFB,deniskropp/DirectFB,lancebaiyouview/DirectFB,kevleyski/directfb,kaostao/directfb,kevleyski/DirectFB-1,kaostao/directfb,kevleyski/DirectFB-1,deniskropp/DirectFB,jcdubois/DirectFB,sklnet/DirectFB,sklnet/DirectFB,Distrotech/DirectFB