HNCP: Add a test capture file

HNCP: Add a test capture file

This capture file triggered a buffer over-read with the 4.9.2 release
fixed in the 4.9.3 release.

With a previous update (511915bef7e4de2f31b8d9f581b4a44b0cfbcf53),
the problem no longer exists.
Thus no fix needed.

The pcap file was renamed from pcapng to pcap because it is.

Update the output of the test accordingly.

Partial update from 83a412a5275cac973c5841eca3511c766bed778d
in 4.9 branch.