[clang-format] Fixed indent issue when adding a comment at the end of a return...

[clang-format] Fixed indent issue when adding a comment at the end of a return type in named function declaration.

Differential Revision: https://reviews.llvm.org/D30646

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@297143 91177308-0d34-0410-b5e6-96231b3b80d8