pprint: fix RuboCop style.
pprint: fix RuboCop style.

See https://github.com/Homebrew/brew/pull/7867.

maxim-belkin/homebrew-core,rwhogg/homebrew-core,rwhogg/homebrew-core,Linuxbrew/homebrew-core,Linuxbrew/homebrew-core,maxim-belkin/homebrew-core