[ruby/irb] Fix warnings in test_cmd.rb
Fixes this warning:
warning: assigned but unused variable - err
https://github.com/ruby/irb/commit/298fcb57a3
[ruby/irb] Fix warnings in test_cmd.rb
Fixes this warning:
https://github.com/ruby/irb/commit/298fcb57a3