Unnecessary check in AbstractDrop.producerFinished
Unnecessary check in AbstractDrop.producerFinished

The symmetric AppDrop.dropCompleted method doesn't perform this check. It also
means (currently) that we're always referencing the producer drop (either via
Pyro at the moment, or via the next mechanism we choose to use).

Signed-off-by: Rodrigo Tobar <bd955c861cbec2e41c0959cf13c7f573fa307e58@icrar.org>

steve-ord/daliuge,steve-ord/daliuge,steve-ord/daliuge,steve-ord/daliuge,steve-ord/daliuge,steve-ord/daliuge,steve-ord/daliuge