svga: Prevent potential null pointer deference in vmw_surface.c.
diff --git a/src/gallium/winsys/drm/vmware/core/vmw_surface.c b/src/gallium/winsys/drm/vmware/core/vmw_surface.c
index 9ec4bf9..c19e556 100644
--- a/src/gallium/winsys/drm/vmware/core/vmw_surface.c
+++ b/src/gallium/winsys/drm/vmware/core/vmw_surface.c
@@ -39,7 +39,7 @@
    struct pipe_reference *dst_ref;
    struct vmw_svga_winsys_surface *dst = *pdst;
    
-   if(*pdst == src || pdst == NULL)
+   if(pdst == NULL || *pdst == src)
       return;
    
    src_ref = src ? &src->refcnt : NULL;