wined3d/d3d9: Set the initial scissor rect to the window size

[Henri Verbeet]

2008/8/23 Stefan Dösinger <stefan at codeweavers.com>:
> Does "WINED3DSURFACE_DESC desc = {0};" set all the pointers in WINED3DSURFACEDESC to NULL? I am not sure about this. (At some point we may also want to de-pointerize WINED3DSURFACEDESC like we've done with the other structures)
>
It initializes the struct with zeroes.