ladspa: call cleanup function if given
ladspa: call cleanup function if given

Some plugins have cleanup functions to deallocate memory after
instantiation.  This must be called after deactivate.

cbagwell/sox,uklauer/sox,cbagwell/sox,davel/sox,davel/sox,davel/sox,davel/sox,uklauer/sox,CaptainHayashi/sox,CaptainHayashi/sox,Distrotech/sox,pcqpcq/sox,uklauer/sox,CaptainHayashi/sox,Distrotech/sox,uklauer/sox,pcqpcq/sox,Distrotech/sox,cbagwell/sox,pcqpcq/sox,CaptainHayashi/sox,Distrotech/sox,cbagwell/sox,pcqpcq/sox