clang-format: Fix ObjC method exprs with variadic parameters.

Before:
  _versionLabel.text = [
    NSString stringWithFormat:NSLocalizedString(@"version: %@", @"Label"),
    [NSBundle mainBundle].infoDictionary[@"CFBundleShortVersionString"]
  ];

After:
  _versionLabel.text =
      [NSString stringWithFormat:NSLocalizedString(@"version: %@", @"Label"),
          [NSBundle mainBundle].infoDictionary[@"CFBundleShortVersionString"]];

This fixed llvm.org/PR17695.

git-svn-id: http://llvm.org/svn/llvm-project/cfe/trunk@193475 91177308-0d34-0410-b5e6-96231b3b80d8