netfilter: nf_tables: fix wrong datatype in nft_validate_data_load()

This patch fixes dictionary mappings, eg.

 add rule ip filter input meta dnat set tcp dport map { 22 => 1.1.1.1, 23 => 2.2.2.2 }

The kernel was returning -EINVAL in nft_validate_data_load() since
the type of the set element data that is passed was the real userspace
datatype instead of NFT_DATA_VALUE.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nf_tables_api.c

@@ -2382,7 +2382,9 @@ static int nf_tables_bind_check_setelem(const struct nft_ctx *ctx,
 	enum nft_registers dreg;
 
 	dreg = nft_type_to_reg(set->dtype);
-	return nft_validate_data_load(ctx, dreg, &elem->data, set->dtype);
+	return nft_validate_data_load(ctx, dreg, &elem->data,
+				      set->dtype == NFT_DATA_VERDICT ?
+				      NFT_DATA_VERDICT : NFT_DATA_VALUE);
 }
 
 int nf_tables_bind_set(const struct nft_ctx *ctx, struct nft_set *set,