New review comment by ahesford on void-packages repository

https://github.com/void-linux/void-packages/pull/37139#discussion_r874760351

Comment:
What problem does this fix?

`rm -rf "/var/lib/dkms/$VAR"` is pretty dangerous when the vars haven't been carefully sanitized. If there's ever a format change in the DKMS output, this could break horribly.