wined3d: Prevent crash when blit_priv is NULL.

[Konrad Rzepecki]

Might&Magic VII from gog.com crash in bink movie plaing:

Backtrace:
=>0 0x7e70c4b9 arbfp_blit_set+0x28b(blit_priv=0x0(nil), gl_info=0x135b08, surface=0x1dc788) [/mnt/skopia/devel/winegit/wine/dlls/wined3d/arb_program_shader.c:7058] in wined3d (0x0033f98c)
  1 0x7e70d3db arbfp_blit_surface+0xa2(device=0x16cdc0, src_surface=0x1dc788, src_rect=0x33fa74, dst_surface=0x168140, dst_rect_in=0x33fa84, blit_op=BLIT_OP_BLIT, Filter=0x2) [/mnt/skopia/devel/winegit/wine/dlls/wined3d/arb_program_shader.c:7192] in wined3d (0x0033f9dc)
  2 0x7e7d28f7 IWineD3DSurfaceImpl_BltOverride+0xf1b(dst_surface=0x168140, DestRect=0x33fcf8, src_surface=0x1dc788, SrcRect=0x33fce8, flags=0x1000000, DDBltFx=(nil), Filter=WINED3DTEXF_LINEAR) [/mnt/skopia/devel/winegit/wine/dlls/wined3d/surface.c:3787] in wined3d (0x0033fbac)
  3 0x7e7d3013 IWineD3DSurfaceImpl_Blt+0x29e(iface=0x168140, DestRect=0x33fcf8, src_surface=0x1dc788, SrcRect=0x33fce8, flags=0x1000000, DDBltFx=(nil), Filter=WINED3DTEXF_LINEAR) [/mnt/skopia/devel/winegit/wine/dlls/wined3d/surface.c:3930] in wined3d (0x0033fc2c)
  4 0x7e8687f2 ddraw_surface7_Blt+0x380(iface=0x135308, DestRect=0x33fcf8, SrcSurface=0x1dc560, SrcRect=0x33fce8, Flags=0x1000000, DDBltFx=(nil)) [/mnt/skopia/devel/winegit/wine/dlls/ddraw/surface.c:908] in ddraw (0x0033fc9c)
  5 0x004a18cd in mm7-rel (+0xa18cc) (0x0033fcc8)
  6 0x004beda4 in mm7-rel (+0xbeda3) (0x0033fd08)
  7 0x004be721 in mm7-rel (+0xbe720) (0x00000000)
---
 dlls/wined3d/surface.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/dlls/wined3d/surface.c b/dlls/wined3d/surface.c
index 745bd77..baa032b 100644
--- a/dlls/wined3d/surface.c
+++ b/dlls/wined3d/surface.c
@@ -3924,8 +3924,8 @@ static HRESULT WINAPI IWineD3DSurfaceImpl_Blt(IWineD3DSurface *iface, const RECT
     }
 
     /* Special cases for RenderTargets */
-    if ((This->resource.usage & WINED3DUSAGE_RENDERTARGET)
-            || (src && (src->resource.usage & WINED3DUSAGE_RENDERTARGET)))
+    if (This->resource.device->blit_priv && ((This->resource.usage & WINED3DUSAGE_RENDERTARGET)
+            || (src && (src->resource.usage & WINED3DUSAGE_RENDERTARGET))))
     {
         if (SUCCEEDED(IWineD3DSurfaceImpl_BltOverride(This, DestRect, src, SrcRect, flags, DDBltFx, Filter)))
             return WINED3D_OK;
-- 
1.7.4.1