clang-format: Fix AlwaysBreakAfterDefinitionReturnType in Stroutrup style

Before:
  template <class T>
  T *f(T &c)  // Problem here: no line break before f
  {
    return NULL;
  }

After:
  template <class T>
  T *
  f(T &c)
  {
    return NULL;
  }

Patch by Marek Kurdej, thank you!

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@215633 91177308-0d34-0410-b5e6-96231b3b80d8