libweston: Make weston_keyboard destruction safe

Ensure the server can safely handle client requests for wl_keyboard
resources that have become inert due to a weston_keyboard object
destruction.

This change involves, among other things, setting the weston_keyboard
object, instead of the weston_seat object, as the user data for
wl_keyboard resources.  Although this is not strictly required at the
moment (since no code is using the wl_keyboard user data), it makes the
code safer:

 * It makes more sense conceptually.
 * It is consistent with how wl_pointer resources are handled.
 * It allows us to clear the user data during weston_keyboard
   destruction, so other code can check whether the resource is inert.

Signed-off-by: Alexandros Frantzis <alexandros.frantzis@collabora.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
1 file changed