Set the outbuf acquire fence after we actually have it.

In GLES-only mode, we don't have the outbuf acquire fence until after
GLES composition is done for the frame. We were setting the fence in
HWC's state immediately after dequeueing the buffer from the consumer,
before GLES had started. This fence got passed through HWC and on to
the consumer, so the consumer was reading the buffer before GLES was
done writing to it.

Now we update HWC's state just before set(), when we know we have the
right fence.

Bug: 11000763
Change-Id: Iea9db4c69634c352dc2d600f0bdb6bef2a432636