drbd: Make sure we do not send state updates during an empty resync [Bugz 271]

This is a race condition that existed for ages.
The previous commit reduces the window, this one closes it.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
1 file changed