clang-format: Fix regression introduced in r221609.

Before:
  void f() { f(a, c *d); }

After:
  void f() { f(a, c * d); }

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@222128 91177308-0d34-0410-b5e6-96231b3b80d8