ext4: add positive int attr pointer to avoid sysfs variables overflow

The following variables controlled by the sysfs interface are of type
int and are normally used in the range [0, INT_MAX], but are declared as
attr_pointer_ui, and thus may be set to values that exceed INT_MAX and
result in overflows to get negative values.

  err_ratelimit_burst
  msg_ratelimit_burst
  warning_ratelimit_burst
  err_ratelimit_interval_ms
  msg_ratelimit_interval_ms
  warning_ratelimit_interval_ms

Therefore, we add attr_pointer_pi (aka positive int attr pointer) with a
value range of 0-INT_MAX to avoid overflow.

Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20240319113325.3110393-7-libaokun1@huawei.com


Signed-off-by: Theodore Ts'o <tytso@mit.edu>