Update cmd_print.c

[rickhg12hs]

Swapped ; for : to align format with description.

Your checklist for this pull request

• I've read the guidelines for contributing to this repository
• I made sure to follow the project's coding style
• I've documented or updated the documentation of every function and struct this PR changes. If not so I've explained why.
• I've added tests that prove my fix is effective or that my feature works (if possible)
• I've updated the rizin book with the relevant information (if needed)

Detailed description

It's just a fix for a documented example.
...

Test plan

This fix just shows the correct format for the description.
...

Closing issues

...