Patch to allow DirectFB target to report a correct screen size.

Fixes Bugzilla #399.

--HG--
branch : SDL-1.2

src/video/directfb/SDL_DirectFB_video.c

@@ -460,6 +460,8 @@ int DirectFB_VideoInit(_THIS, SDL_PixelFormat *vformat)
   this->info.blit_hw_A    = 1;
   this->info.blit_fill    = 1;
   this->info.video_mem    = caps.video_memory / 1024;
+  this->info.current_w    = dlc.width;  
+  this->info.current_h    = dlc.height;
 
   HIDDEN->initialized = 1;
   HIDDEN->dfb         = dfb;