xdg-shell: weston-simple-dmabuf-feedback asserstion failed.

[yuiiio]

I use sway wlroots (git), and test weston-simple-dmabuf-feedback and get

weston-simple-dmabuf-feedback: 
../clients/simple-dmabuf-feedback.c:573: create_dmabuf_buffer: Assertion `buf->bo && "error: could not create GBM bo for buffer"' failed.

weston and kwin compositor success with this client.

revert this client's commit will also succeed in sway.
https://gitlab.freedesktop.org/wayland/weston/-/commit/34400d7d1686d53ceaf79ff1142349a1a171db68

[yuiiio]

WAYALND_DEBUG=server output
sway:

[3980401.206] [email protected]_title("simple-dmabuf-feedback")
[3980401.208] [email protected]_app_id("org.freedesktop.weston.simple-dmabuf-feedback")
[3980401.210] [email protected]_fullscreen(nil)
[3980401.211] [email protected]()
[3980401.215] [email protected](new id wl_callback@12)
[3980401.217]  -> [email protected](73)
[3980401.218]  -> [email protected]_id(12)
[3980401.220]  -> [email protected](0, 0, array[0])
[3980401.222]  -> [email protected](73)

weston:

[3946016.483] [email protected]_title("simple-dmabuf-feedback")
[3946016.485] [email protected]_app_id("org.freedesktop.weston.simple-dmabuf-feedback")
[3946016.488] [email protected]_fullscreen(nil)
[3946016.495] [email protected]()
[3946016.499] [email protected](new id wl_callback@12)
[3946016.502]  -> [email protected](69)
[3946016.505]  -> [email protected]_id(12)
[3946016.507]  -> [email protected](1268, 1023, array[4])
[3946016.515]  -> [email protected](70)
[3946017.707] [email protected]_configure(70)

I think it related to this #2176