fprint-list-supported-devices: Do not double-free usb_list
We were leaking the spi_list instead.
See: https://gitlab.freedesktop.org/libfprint/fprint.freedesktop.org/-/jobs/38110137
We were leaking the spi_list instead.
See: https://gitlab.freedesktop.org/libfprint/fprint.freedesktop.org/-/jobs/38110137