In case of an error in dfb_surface_dump() only release the palette if non-NULL.
In case of an error in dfb_surface_dump() only release the palette if non-NULL.

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