Fix memset of qsolist buffer

[seporaitis]

Description

Accidentally missed the sizeof(char) in memset call. This is potentially harmless, but still - inconsistent.

Motivation and Context

Maybe in some universe where char is not a single byte (AFAIK none such exists) - it could lead in not clearing up of the whole buffer.

How Has This Been Tested?

Ran src/lhl and interacted with UI.

Screenshots (if appropriate):

Types of changes

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• [x] My code follows the code style of this project.
• [ ] My change requires a change to the documentation.
  • [ ] I have updated the documentation accordingly.
• [ ] I have updated HISTORY document.
  • [ ] I have referenced pull request and/or issue next to the change.
• [x] I have read the CONTRIBUTING document.
• [x] All new and existing tests passed.
  • [ ] I have added tests to cover my changes.