ipaddrlabel: use uint32_t instead of int32_t

As both linux kernel and function ipaddrlabel_modify use unsigned int for
label. We should also use unsigned int value when print addrlabel in case of
misunderstanding.
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>

ip/ipaddrlabel.c

@@ -86,10 +86,10 @@ int print_addrlabel(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg
 	if (ifal->ifal_index)
 		fprintf(fp, "dev %s ", ll_index_to_name(ifal->ifal_index));
 
-	if (tb[IFAL_LABEL] && RTA_PAYLOAD(tb[IFAL_LABEL]) == sizeof(int32_t)) {
-		int32_t label;
+	if (tb[IFAL_LABEL] && RTA_PAYLOAD(tb[IFAL_LABEL]) == sizeof(uint32_t)) {
+		uint32_t label;
 		memcpy(&label, RTA_DATA(tb[IFAL_LABEL]), sizeof(label));
-		fprintf(fp, "label %d ", label);
+		fprintf(fp, "label %u ", label);
 	}
 
 	fprintf(fp, "\n");