ScopedFileDescriptor: better error on close

These were hidden/silent.

Fixes: 171065651
Test: introduce test bug and see:
12-15 20:12:06.806 11035 11057 E android.binder.cts: Could not close FD
53: Bad file descriptor

Change-Id: I0845a6f9cc6ecc146f3571d4df1e089d4c7aac81