Fix invalid formatting with spaces before trailing comments.

Fix invalid formatting with spaces before trailing comments.

In google style, trailing comments are separated by two spaces. This
patch fixes the counting of these spaces and prevents clang-format from
creating a line with 81 columns.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@174879 91177308-0d34-0410-b5e6-96231b3b80d8