i#1657 clang build failure: remove unused variables
i#1657 clang build failure: remove unused variables

Remove unused variables from annotations.c to fix clang build failures.

Fixes #1657

Review-URL: https://codereview.appspot.com/217610043

bl4ckic3/dynamorio,AmesianX/dynamorio,code4bones/dynamorio,code4bones/dynamorio,bl4ckic3/dynamorio,daksunt/dynamorio,sigma-random/dynamorio,bl4ckic3/dynamorio,sigma-random/dynamorio,sigma-random/dynamorio,AmesianX/dynamorio,AmesianX/dynamorio,bl4ckic3/dynamorio,daksunt/dynamorio,code4bones/dynamorio,sigma-random/dynamorio,sigma-random/dynamorio,daksunt/dynamorio,code4bones/dynamorio,bl4ckic3/dynamorio,daksunt/dynamorio,AmesianX/dynamorio,daksunt/dynamorio,code4bones/dynamorio,AmesianX/dynamorio