batman-adv: fix counter summary length

Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Acked-by: Martin Hundebøll <martin@hundeboll.net>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
diff --git a/net/batman-adv/main.h b/net/batman-adv/main.h
index 8193650..b8d4ac1 100644
--- a/net/batman-adv/main.h
+++ b/net/batman-adv/main.h
@@ -265,9 +265,8 @@
 static inline uint64_t batadv_sum_counter(struct batadv_priv *bat_priv,
 					  size_t idx)
 {
-	uint64_t *counters;
+	uint64_t *counters, sum = 0;
 	int cpu;
-	int sum = 0;
 
 	for_each_possible_cpu(cpu) {
 		counters = per_cpu_ptr(bat_priv->bat_counters, cpu);