rust: drm: pin ioctl Device reference to Normal context

Explicitly annotate the Device reference produced by from_raw() in the
ioctl dispatch macro as Device<_, Normal>. Without this annotation, the
context is inferred from the handler's first parameter type, which would
allow a handler declaring &Device<T, Registered> to obtain a Registered
reference without runtime proof via RegistrationGuard.

Reviewed-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Tested-by: Deborah Brouwer <deborah.brouwer@collabora.com>
Link: https://patch.msgid.link/20260628145406.2107056-11-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

rust/kernel/drm/ioctl.rs

@@ -134,7 +134,8 @@ macro_rules! declare_drm_ioctls {
                             // FIXME: Currently there is nothing enforcing that the types of the
                             // dev/file match the current driver these ioctls are being declared
                             // for, and it's not clear how to enforce this within the type system.
-                            let dev = $crate::drm::device::Device::from_raw(raw_dev);
+                            let dev: &$crate::drm::device::Device<_, $crate::drm::Normal> =
+                                $crate::drm::device::Device::from_raw(raw_dev);
 
                             // Enforce that the handler accepts higher-ranked
                             // lifetimes, preventing it from requiring 'static