selftests/damon/damon_nr_regions: sort collected regiosn before checking with min/max boundaries

damon_nr_regions.py starts DAMON, periodically collect number of regions
in snapshots, and see if it is in the requested range.  The check code
assumes the numbers are sorted on the collection list, but there is no
such guarantee.  Hence this can result in false positive test success. 
Sort the list before doing the check.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: 7814973 ("selftests/damon: implement test for min/max_nr_regions")
Signed-off-by: SeongJae Park <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

Author: sjp38

tools/testing/selftests/damon/damon_nr_regions.py

@@ -65,6 +65,7 @@ def test_nr_regions(real_nr_regions, min_nr_regions, max_nr_regions):
 
     test_name = 'nr_regions test with %d/%d/%d real/min/max nr_regions' % (
             real_nr_regions, min_nr_regions, max_nr_regions)
+    collected_nr_regions.sort()
     if (collected_nr_regions[0] < min_nr_regions or
         collected_nr_regions[-1] > max_nr_regions):
         print('fail %s' % test_name)