pam_login_access: Fix negative entry matching logic
PR: 252194
Approved by: so
Security: CVE-2020-25580
Security: FreeBSD-SA-21:03.pam_login_access
(cherry picked from commit 6ab923cbca8759503a08683a5978b9ebf5efd607)
(cherry picked from commit c99e3e2d96935ae4d61948bf7660e9b9c2afb4d9)