Fixed last month, but forgotten about.

commit 599db456140749533c76d826a5e81c12af00c692
Author: G. Branden Robinson <g.branden.robinson@gmail.com>
Date:   Thu Aug 24 01:40:13 2023 -0500

    [mm]: Fix code style nits in mmroff.

    * contrib/mm/mmroff.pl: Fix code style nits; resolve Perl warnings.
      Initialize scalars `max_height` and `max_width` before using them.
      Add to `cur` hash instead of reinitializing it when reading "PIC id"
      comment from input.

      (ps_calc): Return early if bounding box keys in `cur` hash not
      populated.

      (psbb): Use `return` instead of `next` to exit early from non-loop.
      Improve diagnostic message: identify who is speaking, what operation
      failed, and end with newline.