selftests/damon/sysfs: test tried_regions/total_bytes file

Update sysfs.sh DAMON selftest for checking existence of 'total_bytes'
file under the 'tried_regions' directory of DAMON sysfs interface.

Link: https://lkml.kernel.org/r/20230802213222.109841-4-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

tools/testing/selftests/damon/sysfs.sh

@@ -84,6 +84,7 @@ test_tried_regions()
 {
 	tried_regions_dir=$1
 	ensure_dir "$tried_regions_dir" "exist"
+	ensure_file "$tried_regions_dir/total_bytes" "exist" "400"
 }
 
 test_stats()