Added missing pthread_rwlock_destroy().
Added missing pthread_rwlock_destroy().

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