tests: Annotate fall-through switch case (Coverity).

Signed-off-by: Józef Kucia <jkucia@codeweavers.com>
Signed-off-by: Henri Verbeet <hverbeet@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>

tests/d3d12.c

@@ -14534,6 +14534,7 @@ static void test_typed_uav_store(void)
         {
             default:
                 trace("Unhandled format %#x.\n", tests[i].format);
+                /* fall-through */
             case DXGI_FORMAT_R32_FLOAT:
                 check_sub_resource_float(resource, 0, queue, command_list, tests[i].result.f, 2);
                 break;