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.

lib/prototypes.h

@@ -114,6 +114,9 @@ extern void dolastlog (struct lastlog *ll,
                        const char *line,
                        const char *host);
 
+/* login_nopam.c */
+extern int login_access (const char *user, const char *from);
+
 /* loginprompt.c */
 extern void login_prompt (const char *, char *, int);