Specify checksums properly for llgs test suite packets.

Summary: These checksums are ignored by llgs but some implementations require them to be specified properly.

Test Plan: Re-run llgs tests with the checksums and make sure we don't break anything.

Reviewers: tfiala, clayborg

Subscribers: lldb-commits

Differential Revision: http://reviews.llvm.org/D6254

llvm-svn: 221927