i965: Don't special case the batchbuffer when reference counting.

i965: Don't special case the batchbuffer when reference counting.

We don't need to special case the batch - when we add the batch to the
validation list, we can simply increase the refcount to 2, and when we
make a new batch, we'll drop it back down to 1 (when unreferencing all
buffers in the validation list).  The final reference is still held by
brw->batch.bo, as it was before.

This removes the special case from a bunch of loops.

Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>