ospf6d: add format attributes

[Sebastian Benoit]

In ospf6d, add format attributes to the proper functions and then fix the
warning in rde.c

ok?

diff --git log.h log.h
index 0cc7403..8cccd8f 100644
--- log.h
+++ log.h
@@ -23,14 +23,22 @@
 
 void    log_init(int);
 void    log_verbose(int);
-void    logit(int, const char *, ...);
-void    vlog(int, const char *, va_list);
-void    log_warn(const char *, ...);
-void    log_warnx(const char *, ...);
-void    log_info(const char *, ...);
-void    log_debug(const char *, ...);
-void    fatal(const char *) __dead;
-void    fatalx(const char *) __dead;
+void    logit(int, const char *, ...)
+               __attribute__((__format__ (printf, 2, 3)));
+void    vlog(int, const char *, va_list)
+               __attribute__((__format__ (printf, 2, 0)));
+void    log_warn(const char *, ...)
+               __attribute__((__format__ (printf, 1, 2)));
+void    log_warnx(const char *, ...)
+               __attribute__((__format__ (printf, 1, 2)));
+void    log_info(const char *, ...)
+               __attribute__((__format__ (printf, 1, 2)));
+void    log_debug(const char *, ...)
+               __attribute__((__format__ (printf, 1, 2)));
+void    fatal(const char *) __dead
+               __attribute__((__format__ (printf, 1, 0)));
+void    fatalx(const char *) __dead
+               __attribute__((__format__ (printf, 1, 0)));
 
 const char     *log_in6addr(const struct in6_addr *);
 const char     *log_in6addr_scope(const struct in6_addr *, unsigned int);
diff --git rde.c rde.c
index 1de5d14..1d4b426 100644
--- rde.c
+++ rde.c
@@ -356,7 +356,7 @@ rde_dispatch_imsg(int fd, short event, void *bula)
                                }
                        }
                        if (l != 0)
-                               log_warnx("rde_dispatch_imsg: peerid %lu, "
+                               log_warnx("rde_dispatch_imsg: peerid %u, "
                                    "trailing garbage in Database Description "
                                    "packet", imsg.hdr.peerid);
 
@@ -387,7 +387,7 @@ rde_dispatch_imsg(int fd, short event, void *bula)
                                    ntohs(v->lsa->hdr.len));
                        }
                        if (l != 0)
-                               log_warnx("rde_dispatch_imsg: peerid %lu, "
+                               log_warnx("rde_dispatch_imsg: peerid %u, "
                                    "trailing garbage in LS Request "
                                    "packet", imsg.hdr.peerid);
                        break;