gn build: Fix clang-tidy dep on ClangSACheckers.

Patch by Mirko Bonadei <mbonadei@webrtc.org>!

Differential Revision: https://reviews.llvm.org/D57998


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@353657 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed