Fix order of ED/swap blocks during checkpoint reading.

For some reason the order of reading the swap state and the essential
dynamics (ED) state were mixed up in read_checkpoint(), which lead to
unreadable state files if both ED and swap functionality were used.
This fix changes the order of those blocks to be consistent with
write_checkpoint().

Change-Id: Ie234486b990861decef9e00fc5125f867001f814