Historically ipfstat listings and stats only listed IPv4 or IPv6 output.
ipfstat would list IPv4 outputs by default while -6 would produce IPv6
outputs. This commit combines the ipfstat -i and -o outputs into one
listing of IPv4 and IPv6 rules. The -4 option lists only IPv4 rules
(as the default before) while -6 continues to list only rules that affect
IPv6.

PR: 247952
Reported by: joeb1@a1poweruser.com
MFC after: 1 week