[NFC] Use LLVM naming conventions within FileDistance

Reviewed by: sammccall

Differential Revision: https://reviews.llvm.org/D51527

git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@341182 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed