pfr_insert_kentry() returned the error of pfr_route_kentry() and
leaked the entry it had created; pfr_insert_kentries() stopped at the
first entry it could not route and leaked it and the rest of the work
queue, which no caller frees. Destroy an entry that cannot be routed
and go on with the next.
MFC after: 2 weeks
Sponsored by: Rubicon Communications, LLC ("Netgate")