afs: Enable IPv6 DNS lookups

Remove the restriction on DNS lookup upcalls that prevents ipv6 addresses
from being looked up.

Signed-off-by: David Howells <dhowells@redhat.com>
diff --git a/fs/afs/addr_list.c b/fs/afs/addr_list.c
index 7587fb6..b49ccae 100644
--- a/fs/afs/addr_list.c
+++ b/fs/afs/addr_list.c
@@ -216,7 +216,7 @@
 	_enter("%s", cell->name);
 
 	ret = dns_query("afsdb", cell->name, cell->name_len,
-			"ipv4", &vllist, _expiry);
+			"", &vllist, _expiry);
 	if (ret < 0)
 		return ERR_PTR(ret);