freedreno: clear last_fence after resource tracking
The resource tracking in the clear/draw_vbo/blit paths could itself trigger a flush. Which would update last_fence. So we need to clear last_fence *after* all the dependency tracking. Fixes: ddb7fada ("freedreno: avoid no-op flushes by re-using last-fence") Closes: mesa/mesa#2992 Signed-off-by:Rob Clark <robdclark@chromium.org> Part-of: <mesa/mesa!5188>