Fix up the return value of launch()

This is "obviously" the right thing to do, except of course it's
pure sugar: the return value is not used anywhere. Except if someone
has a script that imports the whole thing somehow and then does
isinstance(dict). Because that is so much easier than submitting
a patch, I can imagine someone, somewhere doing that.

The fix came in a patch by dfg, see review 121851.

Change-Id: I39ddf70dc2d027b7db6e31097400248dc66eb137
Merge "Fix up the return value of launch()"