to #29361128

commit 9ea37e24d4a95dd934a0600d65caa25e409705bb upstream.

iocost_monitor.py broke with recent versions of drgn due to helper
being stricter about types.  Fix it so that it uses the correct type.
Signed-off-by: NTejun Heo <tj@kernel.org>
Suggested-by: NOmar Sandoval <osandov@fb.com>
Signed-off-by: NJiufei Xue <jiufei.xue@linux.alibaba.com>
Reviewed-by: NJoseph Qi <joseph.qi@linux.alibaba.com>