Do not instrument libFuzzer itself when built with -DLLVM_USE_SANITIZE_COVERAGE

Fixes regression from https://reviews.llvm.org/D36295

Differential Revision: https://reviews.llvm.org/D36428

git-svn-id: svn://svn.chromium.org/llvm-project/llvm/trunk/lib/Fuzzer@310305 0b72dbe1-c17f-4bc7-b9db-2b4152be0356
1 file changed