rhashtable: Use rht_obj() instead of manual offset calculation

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

lib/rhashtable.c

@@ -427,7 +427,7 @@ void *rhashtable_lookup(const struct rhashtable *ht, const void *key)
 		if (memcmp(rht_obj(ht, he) + ht->p.key_offset, key,
 			   ht->p.key_len))
 			continue;
-		return (void *) he - ht->p.head_offset;
+		return rht_obj(ht, he);
 	}
 
 	return NULL;
@@ -460,7 +460,7 @@ void *rhashtable_lookup_compare(const struct rhashtable *ht, const void *key,
 	rht_for_each_rcu(he, tbl->buckets[hash], ht) {
 		if (!compare(rht_obj(ht, he), arg))
 			continue;
-		return (void *) he - ht->p.head_offset;
+		return rht_obj(ht, he);
 	}
 
 	return NULL;