Trying to change the acceleration/threshold on Xwayland cannot work, and
the corresponding handler xwl_pointer_control() is a no-op.
Yet, an X11 client trying to change those on the touch device may
possibly cause a crash because the touch device in Xwayland doesn't set
that.
Initialize the touch device's PtrFeedback to make sure that just cannot
happen.
Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Closes: https://gitlab.freedesktop.org/xorg/xserver/-/issues/1137
(cherry picked from commit ab76272a7d)