netfilter: nft_set_bitmap: incorrect bitmap size

priv->bitmap_size stores the real bitmap size, instead of the full
struct nft_bitmap object.

Fixes: 665153ff ("netfilter: nf_tables: add bitmap set type")
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>

net/netfilter/nft_set_bitmap.c

@@ -258,7 +258,7 @@ static int nft_bitmap_init(const struct nft_set *set,
 {
 	struct nft_bitmap *priv = nft_set_priv(set);
 
-	priv->bitmap_size = nft_bitmap_total_size(set->klen);
+	priv->bitmap_size = nft_bitmap_size(set->klen);
 
 	return 0;
 }