orangefs: have ..._clean_interrupted_...() wait for copy to/from daemon

orangefs: have ..._clean_interrupted_...() wait for copy to/from daemon

* turn all those list_del(&op->list) into list_del_init()
* don't pick ops that are already given up in control device
  ->read()/->write_iter().
* have orangefs_clean_interrupted_operation() notice if op is currently
  being copied to/from daemon (by said ->read()/->write_iter()) and
  wait for that to finish.
* when we are done copying to/from daemon and find that it had been
  given up while we were doing that, wake the waiting ..._clean_interrupted_...

As the result, we are guaranteed that orangefs_clean_interrupted_operation(op)
doesn't return until nobody else can see op.  Moreover, we don't need to play
with op refcounts anymore.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>