[SPARK-3546] InputStream of ManagedBuffer is not closed and causes running out of file descriptor

doesn't this close the inputstream prematurely?  Note that the 3ard argument to results is passed in as a closure so it is lazy.

BTW in my new refactoring of this, there is a place where we should explicitly close the streams:

https://github.com/apache/spark/pull/2330/files#diff-27109eb30a77542d377c936e0d134420R295