drm/i915: Fix lock order reversal with cliprects and cmdbuf in non-DRI2 paths.
This introduces allocation in the batch submission path that wasn't there
previously, but these are compatibility paths so we care about simplicity
more than performance.
kernel.org bug #12419.
Signed-off-by: Eric Anholt <eric@anholt.net> Reviewed-by: Keith Packard <keithp@keithp.com> Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>