block: skip cgroups for passthrough io

Even if BLK_CGROUP is enabled, it does not work for passthrough io.
So skip setting up blkg for passthrough bio.

Reduced processing gives ~5% hike in peak-performance workload.

Signed-off-by: Kundan Kumar <kundan.kumar@samsung.com>
Signed-off-by: Kanchan Joshi <joshi.k@samsung.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20231218152722.1768-1-joshi.k@samsung.com


Signed-off-by: Jens Axboe <axboe@kernel.dk>