CatalogJanitor warns about skipping gc of regions during RIT, but does not actually skip

Found while looking for something else.

We claim in a WARN level log line to "Playing-it-safe skipping merge/split gc'ing of regions from hbase:meta while regions-in-transition (RIT)" but do not actually skip because of a missing return.

Playing it safe has proven unnecessary, I would say. Nonetheless here is a patch that adds the missing return, for discussion.