libbinder_ndk: use __assert on host

The problem is that the arguments were out of order. I was lazy here
before because binder couldn't actually run on host, but it's different
now with RPC binder.

Bug: email thread "AIDL and host_supported"
Test: bindeRpcTest
Change-Id: I98313004ab1e3dac6833bd326e7a7f997a017a8b