clang-format: Fix incorrect space removal.

Before:
  Deleted &operator=(const Deleted &)&= default;
  Deleted &operator=(const Deleted &)&&= delete;

After:
  Deleted &operator=(const Deleted &)& = default;
  Deleted &operator=(const Deleted &)&& = delete;

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@200073 91177308-0d34-0410-b5e6-96231b3b80d8