more logging during upr wait_for_data_move

Change-Id: I96fad34a7a5c07f949045fb7f0418a96f45ea841
Reviewed-on: http://review.couchbase.org/36549
Tested-by: Artem Stemkovski <artem@couchbase.com>
Reviewed-by: Aliaksey Artamonau <aliaksiej.artamonau@gmail.com>