dc_clustering: use record as state tuple, fixed type error
dc_clustering: use record as state tuple, fixed type error

A record can be extended more easily than a tuple; when the entries in a tuple are
changed, all occurences of said tuple must be changed as well. When using a record, only
those occurrences which affect the member itself must be changed.

l4u/scalaris-mirror,l4u/scalaris-mirror,l4u/scalaris-mirror,l4u/scalaris-mirror,l4u/scalaris-mirror,l4u/scalaris-mirror