login_access() is used in src/login.c, and defined in src/login_nopam.c

(which lacks a prototype). Move its prototype from src/login.c to
lib/prototypes.h.

src/login.c

@@ -128,8 +128,6 @@ static void setup_tty (void);
 static void check_flags (int, char *const *);
 
 #ifndef USE_PAM
-extern int login_access (const char *, const char *);
-
 static struct faillog faillog;
 
 static void bad_time_notify (void);