Fix Clang 20 build issues

It is observed that with recent change of clang to 20 there are some CI
build issues found on phosphor-user-manager based on readability and
style. I fixed the same

Change-Id: Ief2a902b9970c628b26e908b8c784efe9e524bf6
Signed-off-by: Chandramohan Harkude <chandramohan.harkude@gmail.com>
3 files changed