[LV][REFACTOR] One more tiny fix for printing debug locations in loop vectorizer. Now consistent with the remarks emitter.

Differential Revision: http://reviews.llvm.org/D3821



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209197 91177308-0d34-0410-b5e6-96231b3b80d8