Remove unused variable

[erikhatcher]

Description

The params variable is unused, duplicating the fq that is inside the expression already.

Solution

Removed the unused variable.

Tests

This is a test :)

Checklist

Please review the following and check all that apply:

• I have reviewed the guidelines for How to Contribute and my code conforms to the standards described there to the best of my ability.
• I have created a Jira issue and added the issue ID to my pull request title.
• I have given Solr maintainers access to contribute to my PR branch. (optional but recommended)
• I have developed this patch against the main branch.
• I have run ./gradlew check.
• I have added tests for my changes.
• I have added documentation for the Reference Guide

[erikhatcher]

Thanks, @epugh for the quick thumbs-up. Here's to my first Solr TLP commit not breaking the build :)