BSE: SF2: use module data free function
BSE: SF2: use module data free function

Without free function, crashes could happen because process() was called after
the fluid synth instance was freed.

Signed-off-by: Stefan Westerfeld <eb0877843acc39f8ef6f7269937dee931c372d23@space.twc.de>

swesterfeld/beast,swesterfeld/beast,tim-janik/beast,swesterfeld/beast,tim-janik/beast,tim-janik/beast,swesterfeld/beast,tim-janik/beast,swesterfeld/beast,swesterfeld/beast,tim-janik/beast,tim-janik/beast,tim-janik/beast,swesterfeld/beast