vndk-def: Fix compute_vndk() w/o generic refs

This commit fixes VNDK computation when generic references are not
specified.

Test: ./tests/test_vndk.py
Change-Id: I345f9bf565843a65eabe082a8e7329b773506e91
(cherry picked from commit d85e8cb4b8a3b9326f9f4a430c8f456ff9ec45ca)
16 files changed