Reason is that some tests have poor description in Doxygen tags,
decided to fix that situation in some tests which I understand.
Also remove small misprints from some parts of code.
Update Doxygen tags for the next tests:
test_access_kobject_without_init_access
test_thread_without_kobject_permission
test_bad_syscall
test_syscall_invalid_kobject
Signed-off-by: Maksim Masalski <maksim.masalski@intel.com>