Fix byte-compile warnings

[syohex]

Description

Related Issue

Type of Change

• [x] Improvement (non-breaking change which improves an existing feature)

Checklist

• [ ] I have read the CONTRIBUTING.md document.
• [ ] I have updated the documentation in the README.md file if necessary.
• [ ] I have added an entry to CHANGES.md.
• [ ] I have added tests to cover my changes.
• [x] All new and existing tests passed (using make test).

[mattiase]

While this makes the warning go away (for now), you should probably think about what that warning was trying to tell you. unwind-protect is completely pointless without something meaningful in the unwinding part. If the unwind-protect isn't needed, as in this case, you can just remove it.

You may also want to take a look at the (prog1 ,@body (kill-buffer)) part. The reason for using prog1 is to return the value of the first argument, but which one is that? The ,@body is a splice-in. Fortunately, the call to kill-buffer can be removed as well because with-temp-buffer will do that, so the prog1 is no longer needed. You can also remove the call to erase-buffer because with-temp-buffer always gives you an empty buffer.