tcpdump: Reconnect pfsync printer

[jrm]

Summary

Fixes: ee67461e (tpcdump: Update to 4.99.4)

Test Plan

It looks like I missed hooking in the pfsync printer in ee67461e. I think I messed up when redoing the sub-tree merge of vendor/tcpdump to contrib/tcpdump after 4bf98559. This is the only test I've done so far.

make -C /usr/src/usr.sbin/tcpdump clean
make -C /usr/src/usr.sbin/tcpdump
make -C /usr/src/usr.sbin/tcpdump install
sudo /usr/sbin/tcpdump -i pfsync0

After restarting pf, tcpdump shows

tcpdump: verbose output suppressed, use -v[v]... for full protocol decode
listening on pfsync0, link-type PFSYNC (Packet filter state syncing), snapshot length 262144 bytes
19:47:11.484907 19:47:11.484907 PFSYNCv5 len 48
    clear all count 1
    eof count 1^J

Any suggestions for further tests?