netfilter: nf_tables: elements with timeout below CONFIG_HZ never expire

Element timeout that is below CONFIG_HZ never expires because the
timeout extension is not allocated given that nf_msecs_to_jiffies64()
returns 0. Set timeout to the minimum value to honor timeout.

Fixes: 8e1102d ("netfilter: nf_tables: support timeouts larger than 23 days")
Signed-off-by: Pablo Neira Ayuso <[email protected]>

net/netfilter/nf_tables_api.c

@@ -4593,7 +4593,7 @@ int nf_msecs_to_jiffies64(const struct nlattr *nla, u64 *result)
 		return -ERANGE;
 
 	ms *= NSEC_PER_MSEC;
-	*result = nsecs_to_jiffies64(ms);
+	*result = nsecs_to_jiffies64(ms) ? : !!ms;
 	return 0;
 }