Remove extra whitespace instead of breaking the line in comments when possible.

Summary: Solves the problem described in http://llvm.org/PR17756

Reviewers: klimek

Reviewed By: klimek

CC: cfe-commits, klimek

Differential Revision: http://llvm-reviews.chandlerc.com/D2131

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@194493 91177308-0d34-0410-b5e6-96231b3b80d8