Description of problem:
After updating the RHEL 8 kernel ("dnf update kernel") of a ppc64le system and rebooting, the "needs-restarting -r" or "dnf needs-restarting -r" commands indicate that a reboot is required and the return code of these commands is 1.

Version-Release number of selected component (if applicable):
RHEL 8.5, 8.6 or 8.7 on platform ppc64le

How reproducible:
always

Steps to Reproduce:
1. Install RHEL 8.5, 8.6 or 8.7 on platform ppc64le.
2. Run "needs-restarting -r" (The return code is 0, as expected).
3. Run "dnf update kernel -y" to update the RHEL kernel.
4. Run "needs-restarting -r" again (The return code is 1, as expected).
5. Reboot the system.
6. Log in and run "needs-restarting -r" again (The return code is still 1 but must be 0. See below for more details).

Actual results:
At step 6, the return code is 1 and the output will be similar to:
--->
Updating Subscription Management repositories.
Core libraries or services have been updated since boot-up:
  * dbus
  * dbus-daemon
  * kernel
  * linux-firmware
  * systemd

Reboot is required to fully utilize these updates.
More information: https://access.redhat.com/solutions/27943
<---

Expected results:
At step 6, the return code is 0 and the output is:
--->
No core libraries or services have been updated since boot-up.
Reboot should not be necessary.
<---

Additional info:
I repeated the "Steps to Reproduce" on RHEL 8.6 on x86, s390x and aarch64. On these 3 hardware platforms, after a reboot following a RHEL kernel update, the return code of "needs-restarting -r" is 0, as expected.

Note: https://bugzilla.redhat.com/show_bug.cgi?id=2137935 has a similar summary and description but by testing "stat -c %y /proc/1" which shows the root cause for that bug, I can confirm that the root cause in my case is different. In other words, the output of this stat command is similar to that on not affected systems, and the output of the "uptime" command is as expected on all the systems I tested.