ddraw: Use SetRectEmpty() instead of open coding it.

dlls/ddraw/surface.c

@@ -1436,7 +1436,7 @@ static HRESULT ddraw_surface_blt_clipped(struct ddraw_surface *dst_surface, cons
     }
     else
     {
-        SetRect(&src_rect, 0, 0, 0, 0);
+        SetRectEmpty(&src_rect);
         wined3d_src_texture = NULL;
         src_sub_resource_idx = 0;
     }

dlls/ddraw/tests/d3d.c

@@ -1832,10 +1832,7 @@ static void DeviceLoadTest(void)
 
     /* First test some broken coordinates. */
     loadpoint.x = loadpoint.y = 0;
-    loadrect.left = 0;
-    loadrect.top = 0;
-    loadrect.right = 0;
-    loadrect.bottom = 0;
+    SetRectEmpty(&loadrect);
     hr = IDirect3DDevice7_Load(lpD3DDevice, texture_levels[1][0], &loadpoint, texture_levels[0][0], &loadrect, 0);
     ok(hr==DDERR_INVALIDPARAMS, "IDirect3DDevice7_Load returned: %x\n",hr);