keys: Be more consistent in selection of union members used

key->description and key->index_key.description are same because
they are unioned. But, for readability, using same name for
duplication and validation seems better.
Signed-off-by: Insu Yun <wuninsu@gmail.com>
Signed-off-by: David Howells <dhowells@redhat.com>

security/keys/key.c

@@ -278,7 +278,7 @@ struct key *key_alloc(struct key_type *type, const char *desc,
 
 	key->index_key.desc_len = desclen;
 	key->index_key.description = kmemdup(desc, desclen + 1, GFP_KERNEL);
-	if (!key->description)
+	if (!key->index_key.description)
 		goto no_memory_3;
 
 	atomic_set(&key->usage, 1);