New review comment by paper42 on void-packages repository

https://github.com/void-linux/void-packages/pull/38202#discussion_r929274043

Comment:
The pkgconfig file mentions libusb in Cflags, but not in Requires, do you know if that's a bug upstream?
```
Cflags: -I${includedir}/libairspyhf/ -I/usr/include/libusb-1.0
```