tools/vm/page_owner_sort: fix three trivival places

tools/vm/page_owner_sort: fix three trivival places

The following adjustments are made:

1. Instead of using another array to cull the blocks after sorting,
   reuse the old array.  So there is no need to malloc a new array.

2. When enabling '-f' option to filter out the blocks which have been
   released, only add those have not been released in the list, rather
   than add all of blocks in the list and then do the filtering when
   printing the result.

3. When enabling '-c' option to cull the blocks by comparing
   stacktrace, print the stacetrace rather than the total block.

Link: https://lkml.kernel.org/r/20220306030640.43054-1-yejiajian2018@email.szu.edu.cn
Signed-off-by: Jiajian Ye <yejiajian2018@email.szu.edu.cn>
Cc: <hanshenghong2019@email.szu.edu.cn>
Cc: Sean Anderson <seanga2@gmail.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Yixuan Cao <caoyixuan2019@email.szu.edu.cn>
Cc: <zhangyinan2019@email.szu.edu.cn>
Cc: Zhenliang Wei <weizhenliang@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>