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 dae05d22d64ea218abe5883be539c2b41c20b1fb)