clang-modernize: Fix clang-apply-replacements invocation bug

The command-line for clang-apply-replacements was being mangled due to an
uninitialized variable. gasp! Now fixed.



git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@192033 91177308-0d34-0410-b5e6-96231b3b80d8