bgpd, zebra: Fix format for some metric outputs

Metrics are unsigned values.

  * bgpd/bgp_{debug,route,vty}.c,
  * zebra/zebra_vty.c: replace %d with %u for metrics & distances

Signed-off-by: Jorge Boncompte [DTI2] <jorge@dti2.net>
[reworded commit message]
Signed-off-by: David Lamparter <equinox@diac24.net>
diff --git a/bgpd/bgp_route.c b/bgpd/bgp_route.c
index 087f839..9f8d823 100644
--- a/bgpd/bgp_route.c
+++ b/bgpd/bgp_route.c
@@ -5954,7 +5954,7 @@
 	  if (! CHECK_FLAG (binfo->flags, BGP_INFO_VALID))
 	    vty_out (vty, " (inaccessible)"); 
 	  else if (binfo->extra && binfo->extra->igpmetric)
-	    vty_out (vty, " (metric %d)", binfo->extra->igpmetric);
+	    vty_out (vty, " (metric %u)", binfo->extra->igpmetric);
 	  vty_out (vty, " from %s", sockunion2str (&binfo->peer->su, buf, SU_ADDRSTRLEN));
 	  if (attr->flag & ATTR_FLAG_BIT(BGP_ATTR_ORIGINATOR_ID))
 	    vty_out (vty, " (%s)", inet_ntoa (attr->extra->originator_id));