netfilter: Fix format string mismatch in ip_vs_proto_name()

Fix string mismatch in ip_vs_proto_name()
Signed-off-by: NMasanari Iida <standby24x7@gmail.com>
Signed-off-by: NSimon Horman <horms@verge.net.au>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/ipvs/ip_vs_core.c

@@ -97,7 +97,7 @@ const char *ip_vs_proto_name(unsigned int proto)
 		return "ICMPv6";
 #endif
 	default:
-		sprintf(buf, "IP_%d", proto);
+		sprintf(buf, "IP_%u", proto);
 		return buf;
 	}
 }