frontend: Fix empty volume name label

[Warchamp7]

Description

Fixes an issue reported on Discord where volume name labels were sometimes empty. This bug is somewhat conditional on the length of source names and the geometry of the window at startup.

Motivation and Context

Fix bug.

How Has This Been Tested?

Reproduced the issue locally with Appearance settings set to font size 9 and Compact density and then tested this change to verify it was fixed.

Types of changes

• Bug fix (non-breaking change which fixes an issue)

Checklist:

• I have read the contributing document.
• My code has been run through clang-format.
• My code follows the project's style guidelines
• My code has been tested.
• All commit messages are properly formatted and commits squashed where appropriate.
• I have included updates to all appropriate documentation.