Fix out packet count reporting

This is a little tiny fix, for the similar issue that was fixed in 2.1 a month ago (the 2.1 fix had a mix of v4 and v6 packet counting fixUPS). The 2.0 IPv4-only code just had this 1 little error.
The 2.1 commit was at https://github.com/bsdperimeter/pfsense/commit/4bdfa5dde01c9fe7f84db252ed654d326b8b30f2