Preserve error logic in getPrimaryKeyHandle (#296)
Preserve error logic in getPrimaryKeyHandle (#296)

In `wrappedTPM20.getPrimaryKeyHandle()`, preserve any error from the
short-circuit `tpm2.ReadPublic()` logic, so that we can return it
alongside any failure in `tpm2.CreatePrimary()`

Co-authored-by: Justin King-Lacroix <280a006853061605da110f2d60df1cd900d002ab@google.com>
google/go-attestation,google/go-attestation