NFSv4: Fix up error handling in the state manager main loop.

The nfs4_state_manager should not be looking at the error values when
deciding whether or not to loop round in order to handle a higher priority
state recovery task. It should rather be looking at the clp->cl_state.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>