[IMPORTANT] Fixed memory leak in papi-java

We forgot to free the eventSets we were creating, now when the EventSet
object is garbage collected, we also destroy the underlying PAPI
EventSet.

papi-java @ 16c467d8

-Subproject commit 87258969289a2bd12872568749ee152a136c0fe5
+Subproject commit 16c467d838f2fedcfaa1b51659b98f4c031ab025