gallium: assert that we're not deleting the currently bound shader

src/gallium/drivers/softpipe/sp_state_fs.c

@@ -82,7 +82,10 @@ softpipe_bind_fs_state(struct pipe_context *pipe, void *fs)
 void
 softpipe_delete_fs_state(struct pipe_context *pipe, void *fs)
 {
+   struct softpipe_context *softpipe = softpipe_context(pipe);
    struct sp_fragment_shader *state = fs;
+
+   assert(fs != softpipe->fs);
    
    state->delete( state );
 }