In TCP, connect() can return incorrect error code EINVAL
instead of EADDRINUSE or ECONNREFUSED

PR: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=196035
Differential Revision: https://reviews.freebsd.org/D1982
Reported by: Mark Nunberg <mnunberg@haskalah.org>
Submitted by: Harrison Grundy <harrison.grundy@astrodoggroup.com>
Reviewed by: adrian, jch, glebius, gnn
Approved by: jhb
MFC after: 2 weeks