rust: auxiliary: sample: demonstrate ForLt with invariant Mutex type

Extend the auxiliary driver sample to demonstrate both access patterns:

  - registration_data() with CovariantForLt!(Data<'_>) for the covariant
    data type that holds a plain &'bound reference.

  - registration_data_with() with ForLt!(MutexData<'_>) for an invariant
    data type that wraps a Mutex<&'bound Device>. Since Mutex<T> is
    invariant over T, MutexData cannot implement CovariantForLt and must
    use the closure-based accessor.

Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Link: https://patch.msgid.link/20260626183630.2585057-5-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>

0 files changed, 0 insertions, 0 deletions