Allow arbitrary primary plane scanout formats

This reverts a change accidentally introduced in 9898913 which would
prevent primary plane scanout unless the scanout format matches the
primary plane's swapchain format. Instead the preferred buffer formats
for the primary plane scanout are used again.

src/udev.rs

@@ -618,7 +618,7 @@ impl OutputDevice {
             &mut self.gles,
             textures,
             CLEAR_COLOR,
-            FrameFlags::DEFAULT,
+            FrameFlags::DEFAULT | FrameFlags::ALLOW_PRIMARY_PLANE_SCANOUT_ANY,
         )?;
         let rendered = !frame_result.is_empty;