ffmpeg: Add "libswresample libavcodec" to CVE_PRODUCT
Currently, CVE_PRODUCT only detects vulnerabilities where the product is "ffmpeg".
However, there are also vulnerabilities where the product is "libswresample",
and "libavcodec" as shown below.
https://app.opencve.io/vendors/?vendor=ffmpeg
Therefore, add "libswresample libavcodec" to CVE_PRODUCT to detect vulnerabilities
where the product is "libswresample libavcodec" as well.