Bluetooth devices not available for capture

Trying to capture from my bluetooth with wireshark, I couldn't find my adapter. Here is what I got when running `dumpcap -D` under root user:

    1. usbmon1
    2. usbmon2
    3. usbmon3
    4. usbmon4
    5. p5p1
    6. p6p1
    7. any
    8. lo (Loopback)

Digged in and turns out that `add_or_find_if()` in `inet.c` adds my bluetooth adapter to top of the list based on its rules. But `bt_findalldevs()` in `pcap-bt-linux.c` doesn't update `alldevsp` so the caller cannot see the added item. The only way `bt_findalldevs()` would work is if the bluetooth adapters are added to the list somewhere below the first item. And I assume in tests, this has been the case to date (as the source code seem to have been the same for past 7 years).

I have done a smoke test of running `dumpcap` and the wireshark GUI with this patch to capture HCI packets and it works fine.