tcp: fix RACK and BBR when using VIMAGE enabled kernel
Fix a bug in VNET handling, which occurs when using specific NICs.
PR: 257195
Reviewed by: rrs
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D31212
(cherry picked from commit a730d82378d3cdf5356775ec0c23ad2ca40c5edb)