devices: undo cset 017baf09599f that added timer drain functions.

devices: undo cset 017baf09599f that added timer drain functions.
It's not the right fix for the checkpoint deadlock problem
Brad was having, and creates another bug where the system can
deadlock on restore.  Brad can't reproduce the original bug
right now, so we'll wait until it arises again and then try
to fix it the right way then.