zebra: identify MRIB on debug messages

since the same code handles both URIB and MRIB, the debug messages can
get rather confusing if the RIB isn't identified.  Mark the MRIB in
debug messages so we can distinguish that.

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
diff --git a/zebra/zebra_rib.c b/zebra/zebra_rib.c
index 4ee1a84..8354513 100644
--- a/zebra/zebra_rib.c
+++ b/zebra/zebra_rib.c
@@ -89,9 +89,12 @@
 
   if (rn)
     {
+      rib_table_info_t *info = rn->table->info;
+
       inet_ntop (rn->p.family, &rn->p.u.prefix, buf, INET6_ADDRSTRLEN);
       bptr = buf + strlen(buf);
-      snprintf(bptr, buf + sizeof(buf) - bptr, "/%d", rn->p.prefixlen);
+      snprintf(bptr, buf + sizeof(buf) - bptr, "/%d%s", rn->p.prefixlen,
+               info->safi == SAFI_MULTICAST ? " (MRIB)" : "");
     }
   else
     {