[Debugify] Don't check functions which were skipped

If no debug info was applied to a function, its debug info shouldn't be
checked (it doesn't have any :).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@325297 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed