Fixes <https://issues.guix.gnu.org/57093>.
Reported by Mohammed AMAR-BENSABER <renken@shione.net>.
Previously 'read-with-comments' would enter an infinite loop.
* guix/read-print.scm (read-with-comments)[missing-closing-paren-error]:
New procedure.
Call it when 'loop' as called from 'liip' returns EOF.
* tests/read-print.scm ("read-with-comments: missing closing paren"):
New test.