Remove circular reference from multiresult exception raising

Change-Id: If9e2b449ad7715edf0f4bf2cafe63d2aee319040
Reviewed-on: http://review.couchbase.org/26655
Reviewed-by: Mordechai Nunberg <mnunberg@haskalah.org>
Tested-by: Mordechai Nunberg <mnunberg@haskalah.org>