Improve indentation of assignments.

Before:
unsigned OriginalStartColumn = SourceMgr.getSpellingColumnNumber(
    Current.FormatTok.getStartOfNonWhitespace()) -
                               1;

After:
unsigned OriginalStartColumn =
    SourceMgr.getSpellingColumnNumber(
        Current.FormatTok.getStartOfNonWhitespace()) -
    1;

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@182733 91177308-0d34-0410-b5e6-96231b3b80d8