New review comment by ahesford on void-packages repository

https://github.com/void-linux/void-packages/pull/30599#discussion_r624841626

Comment:
Avoid the sub shell, `${XENSTORED##*/}` works in place of base name.

Better yet, why does this case exist? Just drop the whole test, you already provide a mechanism for people to add `--verbose` In `$XENSTORED_ARGS` if they care.