tests: logging: adjust the structure of logging test cases

Adjust the logging test case code to make them the same as other test
cases which deal with the CONFIG_USERSPACE used. It does not change
the original test logic, but just the file structure changed.

It also corrects the duplicated testsuite name of logging testcases.

Signed-off-by: Enjia Mai <enjia.mai@intel.com>