Accesses to `/etc/libva.conf` and `/etc/igfx_user_feature.txt`

Using Debian sid/unstable intel-media-va-driver-non-free:amd64 21.4.1+ds1-1, and Mozilla Firefox (Nightly) with VA-API, running `sudo opensnoop.bt`, it shows a lot of accesses to `/etc/libva.conf` and `/etc/igfx_user_feature.txt`.

```
$ sudo opensnoop.bt
Attaching 6 probes...
Tracing open syscalls... Hit Ctrl-C to end.
PID COMM FD ERR PATH
6287 DNS Res~ver #33 168 0 /etc/hosts
414 systemd-resolve -1 2 /run/systemd/netif/links/2
414 systemd-resolve -1 2 /run/systemd/netif/links/2
414 systemd-resolve -1 2 /run/systemd/netif/links/2
414 systemd-resolve -1 2 /run/systemd/netif/links/2
6287 FS Broker 9185 -1 2 /etc/libva.conf
6287 FS Broker 9185 -1 2 /etc/libva.conf
6287 FS Broker 9185 -1 2 /etc/libva.conf
6287 FS Broker 9185 -1 2 /etc/libva.conf
6287 FS Broker 9185 -1 2 /etc/libva.conf
6287 FS Broker 9185 -1 2 /etc/libva.conf
6287 FS Broker 9185 -1 2 /etc/libva.conf
6287 FS Broker 9185 -1 2 /etc/libva.conf
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/libva.conf
6287 FS Broker 9185 -1 2 /etc/libva.conf
6287 FS Broker 9185 -1 2 /etc/libva.conf
6287 FS Broker 9185 -1 2 /etc/libva.conf
6287 FS Broker 9185 -1 2 /etc/libva.conf
6287 FS Broker 9185 -1 2 /etc/libva.conf
6287 FS Broker 9185 -1 2 /etc/libva.conf
6287 FS Broker 9185 -1 2 /etc/libva.conf
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/libva.conf
6287 FS Broker 9185 -1 2 /etc/libva.conf
6287 FS Broker 9185 -1 2 /etc/libva.conf
6287 FS Broker 9185 -1 2 /etc/libva.conf
6287 FS Broker 9185 -1 2 /etc/libva.conf
6287 FS Broker 9185 -1 2 /etc/libva.conf
6287 FS Broker 9185 -1 2 /etc/libva.conf
6287 FS Broker 9185 -1 2 /etc/libva.conf
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
6287 FS Broker 9185 -1 2 /etc/igfx_user_feature.txt
```

According to [Video Processing Debug Tool](https://github.com/intel/media-driver/wiki/Video-Processing-Debug-Tool), at least `/etc/igfx_user_feature.txt`, is mainly used for debugging and tracing. As I am using the release version, should the files be queried that often.