intel: Move finish_batch() call before MI_BATCH_BUFFER_END and padding.

intel: Move finish_batch() call before MI_BATCH_BUFFER_END and padding.

On Gen4+, brw_finish_batch() calls brw_emit_query_end(), which emits
some extra PIPE_CONTROLs to capture the current occlusion query data.
Unfortunately, it was being called *after* _intel_batchbuffer_flush
added the MI_BATCH_BUFFER_END, meaning those PIPE_CONTROLs didn't get
inside the batch.

Not only does this likely cause bogus occlusion query values, it can
also cause crashes: with the recent change to use 64-bit depth count
writes on Gen6+, we started emitting an odd-length PIPE_CONTROL, which
happened after the MI_NOOP padding.  This resulted in an odd-length
batch buffer, which resulted in execbuf2 returning -EINVAL and the
application dying with an intel_do_flush_locked failure.

On older generations, finish_batch() doesn't emit any state, so this
change shouldn't have any effect.

Huge thanks to Chris Wilson for helping me figure this out.

NOTE: This is a candidate for stable release branches.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=53311
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Eric Anholt <eric@anholt.net>