throttle: use THROTTLE_MAX/ARRAY_SIZE for hard code

throttle: use THROTTLE_MAX/ARRAY_SIZE for hard code

The first dimension of both to_check and
bucket_types_size/bucket_types_units is used as throttle direction,
use THROTTLE_MAX instead of hard coded number. Also use ARRAY_SIZE()
to avoid hard coded number for the second dimension.

Hanna noticed that the two array should be static. Yes, turn them
into static variables.

Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
Message-Id: <20230728022006.1098509-8-pizhenwei@bytedance.com>
Signed-off-by: Hanna Czenczek <hreitz@redhat.com>