wined3d: Only use stretch_rect_fbo() on surfaces that are FBO attachable.
diff --git a/dlls/wined3d/wined3d_private.h b/dlls/wined3d/wined3d_private.h
index a610b7a..adf6235 100644
--- a/dlls/wined3d/wined3d_private.h
+++ b/dlls/wined3d/wined3d_private.h
@@ -2749,6 +2749,7 @@
 #define WINED3DFMT_FLAG_STENCIL                  0x8
 #define WINED3DFMT_FLAG_RENDERTARGET             0x10
 #define WINED3DFMT_FLAG_FOURCC                   0x20
+#define WINED3DFMT_FLAG_FBO_ATTACHABLE           0x40
 
 struct GlPixelFormatDesc
 {