rust: auxiliary: use `pin_init::zeroed()` for device ID

rust: auxiliary: use `pin_init::zeroed()` for device ID

Replace the previous `unsafe { core::mem::zeroed() }` initialization
for `bindings::auxillary_device_id` with `pin_init::zeroed()`. This removes
the explicit unsafe block and uses the safer pinned zero-initialization
helper.

Suggested-by: Benno Lossin <lossin@kernel.org>
Signed-off-by: Atharv Dubey <atharvd440@gmail.com>
Link: https://github.com/Rust-for-Linux/linux/issues/1189
Link: https://patch.msgid.link/20251129124706.26263-1-atharvd440@gmail.com
Signed-off-by: Danilo Krummrich <dakr@kernel.org>