Commit ca4aa096 fixed waiting for the
structure to get initialised, but it is also possible to break out of
the loop while still in TASK_INTERRUPTIBLE.

Replace the whole thing by wait_event_interruptible, which is much more
readable, and doesn't suffer from these problems.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>