AF9015 driver converted to new DVB USB

AF9015 driver converted!

I finally decided to publish one rather complex DVB USB driver as a demonstration what it looks like. I selected Afatech AF9015 driver as it is one of the most complex and main motivator of whole DVB USB changes. I have also Anysee, AU6610 and EC168 drivers converted, but those are far away complexity compared for AF9015, since not so interesting.

Code size reduced a lot

All-in-all, code size goes down rather much. It was 2084 LOC and now it is 1609 LOC - it is near 500 LOC less. Basically it is all coming from the removed hacks. Now all needed functionality is generalized to the common DVB USB and ugly hacks are removed from the individual driver.

PATCH: af9015: switch to new DVB-USB

Near future plans

I am quite happy for features common DVB USB now supports. I think all but dynamic USB ID are implemented somehow for those I initially planned. There is still much work to do when implementing all correctly and test error paths. There is still at one big technical problem to solve. It is that delayed init which was added to fix firmware loading. I can get it crashing rather easily just repeatedly loading and unloading DVB USB driver... I suspect it is coming from the fact both workqueue running delayed device intialization and USB-core end up same routines. For example workqueue is downloading firmware and at the same time module is unloaded by user. Likely some locking is needed to prevent module unload in that case.