selftests/mm: restore default nr_hugepages value during cleanup in hugetlb_reparenting_test.sh

JIRA: https://issues.redhat.com/browse/RHEL-86180

commit 585a914
Author: Donet Tom <donettom@linux.ibm.com>
Date:   Thu Apr 10 05:07:48 2025 -0500

    selftests/mm: restore default nr_hugepages value during cleanup in hugetlb_reparenting_test.sh

    During cleanup, the value of /proc/sys/vm/nr_hugepages is currently being
    set to 0.  At the end of the test, if all tests pass, the original
    nr_hugepages value is restored.  However, if any test fails, it remains
    set to 0.

    With this patch, we ensure that the original nr_hugepages value is
    restored during cleanup, regardless of whether the test passes or fails.

    Link: https://lkml.kernel.org/r/20250410100748.2310-1-donettom@linux.ibm.com
    Fixes: 29750f7 ("hugetlb_cgroup: add hugetlb_cgroup reservation tests")
    Signed-off-by: Donet Tom <donettom@linux.ibm.com>
    Cc: Li Wang <liwang@redhat.com>
    Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
    Cc: Shuah Khan <shuah@kernel.org>
    Cc: Waiman Long <longman@redhat.com>
    Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Signed-off-by: Li Wang <liwang@redhat.com>

Author: wangli5665

tools/testing/selftests/mm/hugetlb_reparenting_test.sh

@@ -56,7 +56,7 @@ function cleanup() {
   rmdir "$CGROUP_ROOT"/a/b 2>/dev/null
   rmdir "$CGROUP_ROOT"/a 2>/dev/null
   rmdir "$CGROUP_ROOT"/test1 2>/dev/null
-  echo 0 >/proc/sys/vm/nr_hugepages
+  echo $nr_hugepgs >/proc/sys/vm/nr_hugepages
   set -e
 }