iproute: show metrics as an unsigned value

Avoids showing negative metrics.

Signed-off-by: Jorge Boncompte [DTI2] <jorge@dti2.net>
diff --git a/ip/iproute.c b/ip/iproute.c
index c97f979..2d15c01 100644
--- a/ip/iproute.c
+++ b/ip/iproute.c
@@ -404,7 +404,7 @@
 				    abuf, sizeof(abuf)));
 	}
 	if (tb[RTA_PRIORITY])
-		fprintf(fp, " metric %d ", *(__u32*)RTA_DATA(tb[RTA_PRIORITY]));
+		fprintf(fp, " metric %u ", *(__u32*)RTA_DATA(tb[RTA_PRIORITY]));
 	if (r->rtm_flags & RTNH_F_DEAD)
 		fprintf(fp, "dead ");
 	if (r->rtm_flags & RTNH_F_ONLINK)