FROMLIST: rust_binder: remove warning about orphan mappings

This condition occurs if a thread dies while processing a transaction.
We should not print anything in this scenario.

Bug: 442843927
Acked-by: Carlos Llamas <cmllamas@google.com>
Reviewed-by: Joel Fernandes <joelagnelf@nvidia.com>
Link: https://lore.kernel.org/r/20251002-binder-orphan-v1-1-cdc4cffff992@google.com


Change-Id: Ia8747f7deb151f395e9fdbaba8e653ad566c68d3
Signed-off-by: Alice Ryhl <aliceryhl@google.com>