netfilter: nft_numgen: rename until attribute by modulus

The _until_ attribute is renamed to _modulus_ as the behaviour is similar to
other expresions with number limits (ex. nft_hash).

Renaming is possible because there isn't a kernel release yet with these
changes.

Signed-off-by: Laura Garcia Liebana <nevola@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

include/uapi/linux/netfilter/nf_tables.h

@@ -1126,13 +1126,13 @@ enum nft_trace_types {
  * enum nft_ng_attributes - nf_tables number generator expression netlink attributes
  *
  * @NFTA_NG_DREG: destination register (NLA_U32)
- * @NFTA_NG_UNTIL: source value to increment the counter until reset (NLA_U32)
+ * @NFTA_NG_MODULUS: maximum counter value (NLA_U32)
  * @NFTA_NG_TYPE: operation type (NLA_U32)
  */
 enum nft_ng_attributes {
 	NFTA_NG_UNSPEC,
 	NFTA_NG_DREG,
-	NFTA_NG_UNTIL,
+	NFTA_NG_MODULUS,
 	NFTA_NG_TYPE,
 	__NFTA_NG_MAX
 };