proc: snmp6: Use correct type in memset

Reading /proc/net/snmp6 yields bogus values on 32 bit kernels.
Use "u64" instead of "unsigned long" in sizeof().

Fixes: 4a4857b1 ("proc: Reduce cache miss in snmp6_seq_show")
Signed-off-by: Christian Perle <christian.perle@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv6/proc.c

@@ -219,7 +219,7 @@ static void snmp6_seq_show_item64(struct seq_file *seq, void __percpu *mib,
 	u64 buff64[SNMP_MIB_MAX];
 	int i;
 
-	memset(buff64, 0, sizeof(unsigned long) * SNMP_MIB_MAX);
+	memset(buff64, 0, sizeof(u64) * SNMP_MIB_MAX);
 
 	snmp_get_cpu_field64_batch(buff64, itemlist, mib, syncpoff);
 	for (i = 0; itemlist[i].name; i++)