A fix for nouveau preventing the system shutdown and one for a build
warning, and NULL pointer dereference fix for cirrus.
Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20230223083839.5gtmu6i42bnj7pfh@houat