We want the current playing item, rather than the number of items to
choose from. Besides, item-current is _not_ a choice list anyway.

None of the callers actually care about the return value anyway.
When the input item is needed, then playlist_AddInput did and still
does the job.

playlist_ItemGetByInput can be used instead anyway

This reverts commit 8e1f1414.

doSomehting() is not a good function name.

Conflicts:

	modules/codec/dmo/dmo.c

 One input buffer can create multiples output ones and so need to be fetched
before provided a new input one.