Store mutable reference to Device in PasswordSafe

The current implementation of PasswordSafe stored a normal reference to
the Device.  This patch changes the PasswordSafe struct to use a mutable
reference instead.  This allows the borrow checker to make sure that
there is only one PasswordSafe instance at a time.  While this is
currently not needed, it will become important once we can lock the PWS
on the Nitrokey when dropping the PasswordSafe instance.

1 files changed, 0 insertions, 1 deletions

diff --git a/TODO.md b/TODO.md
index 1ff723d..d6a3509 100644
--- a/TODO.md
+++ b/TODO.md
@@ -13,7 +13,6 @@ SPDX-License-Identifier: MIT
 - Clear passwords from memory.
 - Lock password safe in `PasswordSafe::drop()` (see [nitrokey-storage-firmware
   issue 65][]).
-- Disable creation of multiple password safes at the same time.
 - Check timing in Storage tests.
 - Consider restructuring `device::StorageStatus`.