Since we need to hold that mutex anyways to make sure the peer
gets that change in the right position in the data stream,
it makes a lot of sense to use the same mutex to ensure existence
of the tfm.
Signed-off-by: NPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: NLars Ellenberg <lars.ellenberg@linbit.com>