Be able to configure even if CFLAGS is exported containing "-Werror".
Be able to configure even if CFLAGS is exported containing "-Werror".

Fixed warnings.

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