AF_MAX was always intended to be one more than the greatest allocated
value. Jeff broke this in 2013. Unfortunately, a bunch of people then
decided to adapt to the mistake instead of correcting it.
Fixes: 863c7e4562 (" - Reserve a special AF for SDP. The one we were incorrectly using before was taken by another AF.")
MFC after: 3 days
Sponsored by: Klara, Inc.
Sponsored by: NetApp, Inc.
Reviewed by: kevans, glebius
Differential Revision: https://reviews.freebsd.org/D58597
(cherry picked from commit ddd850aa77)
Dag-Erling Smørgrav
2d25276471