clang-format: Fix bug where clang-format would break the code.

Before, it would turn:
  SomeFunction([]() { // Cool function..
    return 43;
  });

Into this:
  SomeFunction([]() { // Cool function.. return 43; });

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@205849 91177308-0d34-0410-b5e6-96231b3b80d8