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/dynroot.c b/fs/afs/dynroot.c
index 983f394..7425f416 100644
--- a/fs/afs/dynroot.c
+++ b/fs/afs/dynroot.c
@@ -46,7 +46,7 @@ static int afs_probe_cell_name(struct dentry *dentry)
 		return 0;
 	}
 
-	ret = dns_query("afsdb", name, len, "ipv4", NULL, NULL);
+	ret = dns_query("afsdb", name, len, "", NULL, NULL);
 	if (ret == -ENODATA)
 		ret = -EDESTADDRREQ;
 	return ret;