Add message to `set_ownership`

Library/Homebrew/cask/lib/hbc/staged.rb

@@ -33,6 +33,7 @@ module Hbc
     def set_ownership(paths, user: current_user, group: "staff")
       full_paths = remove_nonexistent(paths)
       return if full_paths.empty?
+      ohai "Changing ownership of paths required by #{@cask}; your password may be necessary"
       @command.run!("/usr/sbin/chown", args: ["-R", "--", "#{user}:#{group}"] + full_paths,
                                        sudo: true)
     end