The GCDA 402 format won't have a second checksum either.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184864 91177308-0d34-0410-b5e6-96231b3b80d8
Remove unused code. No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184866 91177308-0d34-0410-b5e6-96231b3b80d8