ipvs: stats should not depend on CPU 0

When reading percpu stats we need to properly reset
the sum when CPU 0 is not present in the possible mask.

Signed-off-by: Julian Anastasov <[e-mail]>
Signed-off-by: Simon Horman <[e-mail]>

net/netfilter/ipvs/ip_vs_est.c

···
 				 struct ip_vs_cpu_stats __percpu *stats)
 {
 	int i;
+	bool add = false;
 
 	for_each_possible_cpu(i) {
 		struct ip_vs_cpu_stats *s = per_cpu_ptr(stats, i);
 		unsigned int start;
 		__u64 inbytes, outbytes;
-		if (i) {
+		if (add) {
 			sum->conns += s->ustats.conns;
 			sum->inpkts += s->ustats.inpkts;
 			sum->outpkts += s->ustats.outpkts;
···
 			sum->inbytes += inbytes;
 			sum->outbytes += outbytes;
 		} else {
+			add = true;
 			sum->conns = s->ustats.conns;
 			sum->inpkts = s->ustats.inpkts;
 			sum->outpkts = s->ustats.outpkts;