r300, amd: Oops, a couple more API changes.

Somehow I forgot to commit these.

src/gallium/drivers/r300/r300_texture.c

@@ -72,7 +72,7 @@ static struct pipe_texture*
 
     r300_setup_miptree(tex);
 
-    tex->buffer = screen->buffer_create(screen->winsys, 32,
+    tex->buffer = screen->buffer_create(screen, 32,
                                         PIPE_BUFFER_USAGE_PIXEL,
                                         tex->size);
 

src/gallium/winsys/drm/amd/amd_buffer.c

@@ -231,7 +231,7 @@ struct pipe_surface *amd_surface_from_handle(struct amd_context *amd_context,
 
     pt = pipe_screen->texture_blanket(pipe_screen, &tmpl, &pitch, pb);
     if (pt == NULL) {
-        winsys_buffer_reference(pipe_winsys, &pb, NULL);
+        pipe_buffer_reference(pipe_screen, &pb, NULL);
     }
     ps = pipe_screen->get_tex_surface(pipe_screen, pt, 0, 0, 0,
                                       PIPE_BUFFER_USAGE_GPU_WRITE);