fireworks: make its behaviour at bus reset more reliable

The comment is more important than the code in this patch. It reports there is
a case that the device node is changed as a result of rediscoverying nodes.
Then driver's probe() process run again. This causes changing ALSA device node
and brings 'no such device' error to the application during streaming.
Revert "fireworks/bebob: fix NULL pointer dereference when removed"

This reverts commit e4efb50752c55cad69b7989b75a9f8a5c6922dde.
fireworks/bebob: fix references to wrong pointer

These pointers refer to wrong data and causes a bug when update() process.