Revert "recvfrom should set srcAddress for empty packets"

This reverts commit a6f1e8a691b9542a6ca9fdc9cf391c9b1fbc46dd.

Reason for revert: Broke libcore.io.OsTest#test_recvfrom_concurrentShutdown, recvfrom may also return 0 if the socket is shutdown
Bug: 33483694

Change-Id: I3d22a765352bc9d20fb05d9a271be1c2420ebd46
2 files changed