nfsd: move nfsd4_cstate_assign_replay() earlier in open handling.
Rather than taking the rp_mutex (via nfsd4_cstate_assign_replay) in
nfsd4_cleanup_open_state() (which seems counter-intuitive), take it and
assign rp_owner as soon as possible - in nfsd4_process_open1().
This will support a future change when nfsd4_cstate_assign_replay() might
fail.
Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>