[list] Remove check on element in direct_list_contains_element_EXPENSIVE() used for debugging.
[list] Remove check on element in direct_list_contains_element_EXPENSIVE() used for debugging.

When checking for existence in a list, avoid crashes due to already freed elements being passed
in as a pointer and checked for existence in a list.

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