ilo: remove handle_invalid_batch_bo()

ilo: remove handle_invalid_batch_bo()

It was used to set has_gen6_wa_pipe_control to false when the batch buffer
changed.  When called from emit_flush() and others, it also unset
ILO_3D_PIPELINE_INVALIDATE_BATCH_BO so that the following emit_draw() will not
set has_gen6_wa_pipe_control to false again.  It sounded error-prone and was
just ugly.

We should be able to achieve the same goal by reset has_gen6_wa_pipe_control
in ilo_3d_pipeline_invalidate().  With handle_invalid_batch_bo() gone, the
emit functions can also be inlined.

Signed-off-by: Chia-I Wu <olvaffe@gmail.com>