sys/directdraw/gstdirectdrawsink.c: Bunch of small fixes: remove static function that doesn't exist; declare another ...

Original commit message from CVS:
* sys/directdraw/gstdirectdrawsink.c: (gst_ddrawsurface_finalize),
(gst_directdraw_sink_buffer_alloc),
(gst_directdraw_sink_get_ddrawcaps),
(gst_directdraw_sink_surface_create):
Bunch of small fixes: remove static function that doesn't exist;
declare another one that does; printf format fix; use right macro
when specifying debug category; remove a bunch of unused variables;
#if 0 out an unused chunk of code (partially fixes #439914).