rust_binder: return p from rust_binder_transaction_target_node()

rust_binder: return p from rust_binder_transaction_target_node()

Somehow this got changed to NULL when I ported this to upstream it. No
idea how that happened.

Reported-by: Carlos Llamas <cmllamas@google.com>
Closes: https://lore.kernel.org/r/aXkEiC1sGOGfDuzI@google.com
Fixes: c1ea31205edf ("rust_binder: add binder_transaction tracepoint")
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Carlos Llamas <cmllamas@google.com>
Link: https://patch.msgid.link/20260128-binder-fix-target-node-null-v1-1-78d198ef55a5@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>